encode.c

/* flac - Command-line FLAC encoder/decoder
 * Copyright (C) 2000-2009  Josh Coalson
 * Copyright (C) 2011-2013  Xiph.Org Foundation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#if HAVE_CONFIG_H
#  include <config.h>
#endif

#include <errno.h>
#include <limits.h> /* for LONG_MAX */
#include <math.h> /* for floor() */
#include <stdio.h> /* for FILE etc. */
#include <stdlib.h> /* for malloc */
#include <string.h> /* for strcmp(), strerror() */
#include <sys/stat.h>
#include "FLAC/all.h"
#include "share/alloc.h"
#include "share/grabbag.h"
#include "share/compat.h"
#include "share/private.h"
#include "share/safe_str.h"
#include "encode.h"

#ifdef min
#undef min
#endif
#define min(x,y) ((x)<(y)?(x):(y))
#ifdef max
#undef max
#endif
#define max(x,y) ((x)>(y)?(x):(y))

/* this MUST be >= 588 so that sector aligning can take place with one read */
/* this MUST be < 2^sizeof(size_t) / ( FLAC__MAX_CHANNELS * (FLAC__MAX_BITS_PER_SAMPLE/8) ) */
#define CHUNK_OF_SAMPLES 2048

typedef struct {
	unsigned sample_rate;
	unsigned channels;
	unsigned bits_per_sample; /* width of sample point, including 'shift' bits, valid bps is bits_per_sample-shift */
	unsigned shift; /* # of LSBs samples have been shifted left by */
	unsigned bytes_per_wide_sample; /* for convenience, always == channels*((bps+7)/8), or 0 if N/A to input format (like FLAC) */
	FLAC__bool is_unsigned_samples;
	FLAC__bool is_big_endian;
	FLAC__uint32 channel_mask;
} SampleInfo;

/* this is the client_data attached to the FLAC decoder when encoding from a FLAC file */
typedef struct {
	FLAC__off_t filesize;
	const FLAC__byte *lookahead;
	unsigned lookahead_length;
	size_t num_metadata_blocks;
	FLAC__StreamMetadata *metadata_blocks[1024]; /*@@@ BAD MAGIC number */
	FLAC__uint64 samples_left_to_process;
	FLAC__bool fatal_error;
} FLACDecoderData;

typedef struct {
#if FLAC__HAS_OGG
	FLAC__bool use_ogg;
#endif
	FLAC__bool verify;
	FLAC__bool is_stdout;
	FLAC__bool outputfile_opened; /* true if we successfully opened the output file and we want it to be deleted if there is an error */
	const char *inbasefilename;
	const char *infilename;
	const char *outfilename;

	FLAC__bool treat_warnings_as_errors;
	FLAC__bool continue_through_decode_errors;
	FLAC__bool replay_gain;
	FLAC__uint64 total_samples_to_encode; /* (i.e. "wide samples" aka "sample frames") WATCHOUT: may be 0 to mean 'unknown' */
	FLAC__uint64 unencoded_size; /* an estimate of the input size, only used in the progress indicator */
	FLAC__uint64 bytes_written;
	FLAC__uint64 samples_written;
	unsigned stats_mask;

	SampleInfo info;

	FileFormat format;
	union {
		struct {
			FLAC__uint64 data_bytes;
		} iff;
		struct {
			FLAC__StreamDecoder *decoder;
			FLACDecoderData client_data;
		} flac;
	} fmt;

	FLAC__StreamEncoder *encoder;

	FILE *fin;
	FLAC__StreamMetadata *seek_table_template;
	double progress, compression_ratio;
} EncoderSession;

const int FLAC_ENCODE__DEFAULT_PADDING = 8192;

static FLAC__bool is_big_endian_host_;

static unsigned char ucbuffer_[CHUNK_OF_SAMPLES*FLAC__MAX_CHANNELS*((FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE+7)/8)];
static signed char *scbuffer_ = (signed char *)ucbuffer_;
static FLAC__uint16 *usbuffer_ = (FLAC__uint16 *)ucbuffer_;
static FLAC__int16 *ssbuffer_ = (FLAC__int16 *)ucbuffer_;

static FLAC__int32 in_[FLAC__MAX_CHANNELS][CHUNK_OF_SAMPLES];
static FLAC__int32 *input_[FLAC__MAX_CHANNELS];


/*
 * local routines
 */
static FLAC__bool EncoderSession_construct(EncoderSession *e, encode_options_t options, FLAC__off_t infilesize, FILE *infile, const char *infilename, const char *outfilename, const FLAC__byte *lookahead, unsigned lookahead_length);
static void EncoderSession_destroy(EncoderSession *e);
static int EncoderSession_finish_ok(EncoderSession *e, int info_align_carry, int info_align_zero, foreign_metadata_t *foreign_metadata, FLAC__bool error_on_compression_fail);
static int EncoderSession_finish_error(EncoderSession *e);
static FLAC__bool EncoderSession_init_encoder(EncoderSession *e, encode_options_t options);
static FLAC__bool EncoderSession_process(EncoderSession *e, const FLAC__int32 * const buffer[], unsigned samples);
static FLAC__bool EncoderSession_format_is_iff(const EncoderSession *e);
static FLAC__bool convert_to_seek_table_template(const char *requested_seek_points, int num_requested_seek_points, FLAC__StreamMetadata *cuesheet, EncoderSession *e);
static FLAC__bool canonicalize_until_specification(utils__SkipUntilSpecification *spec, const char *inbasefilename, unsigned sample_rate, FLAC__uint64 skip, FLAC__uint64 total_samples_in_input);
static FLAC__bool verify_metadata(const EncoderSession *e, FLAC__StreamMetadata **metadata, unsigned num_metadata);
static FLAC__bool format_input(FLAC__int32 *dest[], unsigned wide_samples, FLAC__bool is_big_endian, FLAC__bool is_unsigned_samples, unsigned channels, unsigned bps, unsigned shift, size_t *channel_map);
static void encoder_progress_callback(const FLAC__StreamEncoder *encoder, FLAC__uint64 bytes_written, FLAC__uint64 samples_written, unsigned frames_written, unsigned total_frames_estimate, void *client_data);
static FLAC__StreamDecoderReadStatus flac_decoder_read_callback(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data);
static FLAC__StreamDecoderSeekStatus flac_decoder_seek_callback(const FLAC__StreamDecoder *decoder, FLAC__uint64 absolute_byte_offset, void *client_data);
static FLAC__StreamDecoderTellStatus flac_decoder_tell_callback(const FLAC__StreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data);
static FLAC__StreamDecoderLengthStatus flac_decoder_length_callback(const FLAC__StreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data);
static FLAC__bool flac_decoder_eof_callback(const FLAC__StreamDecoder *decoder, void *client_data);
static FLAC__StreamDecoderWriteStatus flac_decoder_write_callback(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
static void flac_decoder_metadata_callback(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
static void flac_decoder_error_callback(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
static FLAC__bool parse_cuesheet(FLAC__StreamMetadata **cuesheet, const char *cuesheet_filename, const char *inbasefilename, unsigned sample_rate, FLAC__bool is_cdda, FLAC__uint64 lead_out_offset, FLAC__bool treat_warnings_as_errors);
static void print_stats(const EncoderSession *encoder_session);
static void print_error_with_init_status(const EncoderSession *e, const char *message, FLAC__StreamEncoderInitStatus init_status);
static void print_error_with_state(const EncoderSession *e, const char *message);
static void print_verify_error(EncoderSession *e);
static FLAC__bool read_bytes(FILE *f, FLAC__byte *buf, size_t n, FLAC__bool eof_ok, const char *fn);
static FLAC__bool read_uint16(FILE *f, FLAC__bool big_endian, FLAC__uint16 *val, const char *fn);
static FLAC__bool read_uint32(FILE *f, FLAC__bool big_endian, FLAC__uint32 *val, const char *fn);
static FLAC__bool read_uint64(FILE *f, FLAC__bool big_endian, FLAC__uint64 *val, const char *fn);
static FLAC__bool read_sane_extended(FILE *f, FLAC__uint32 *val, const char *fn);
static FLAC__bool fskip_ahead(FILE *f, FLAC__uint64 offset);
static unsigned count_channel_mask_bits(FLAC__uint32 mask);
#if 0
static FLAC__uint32 limit_channel_mask(FLAC__uint32 mask, unsigned channels);
#endif

static FLAC__bool get_sample_info_raw(EncoderSession *e, encode_options_t options)
{
	e->info.sample_rate = options.format_options.raw.sample_rate;
	e->info.channels = options.format_options.raw.channels;
	e->info.bits_per_sample = options.format_options.raw.bps;
	e->info.shift = 0;
	e->info.bytes_per_wide_sample = options.format_options.raw.channels * ((options.format_options.raw.bps+7)/8);
	e->info.is_unsigned_samples = options.format_options.raw.is_unsigned_samples;
	e->info.is_big_endian = options.format_options.raw.is_big_endian;
	e->info.channel_mask = 0;

	return true;
}

static FLAC__bool get_sample_info_wave(EncoderSession *e, encode_options_t options)
{
	FLAC__bool got_fmt_chunk = false, got_data_chunk = false, got_ds64_chunk = false;
	unsigned sample_rate = 0, channels = 0, bps = 0, shift = 0;
	FLAC__uint32 channel_mask = 0;
	FLAC__uint64 ds64_data_size = 0;

	e->info.is_unsigned_samples = false;
	e->info.is_big_endian = false;

	if(e->format == FORMAT_WAVE64) {
		/*
		 * lookahead[] already has "riff\x2E\x91\xCF\x11\xA5\xD6\x28\xDB", skip over remaining header
		 */
		if(!fskip_ahead(e->fin, 16+8+16-12)) { /* riff GUID + riff size + WAVE GUID - lookahead */
			flac__utils_printf(stderr, 1, "%s: ERROR during read while skipping over remaining \"riff\" header\n", e->inbasefilename);
			return false;
		}
	}
	/* else lookahead[] already has "RIFFxxxxWAVE" or "RF64xxxxWAVE" */

	while(!feof(e->fin) && !got_data_chunk) {
		/* chunk IDs are 4 bytes for WAVE/RF64, 16 for Wave64 */
		/* for WAVE/RF64 we want the 5th char zeroed so we can treat it like a C string */
		char chunk_id[16] = { '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0' };

		if(!read_bytes(e->fin, (FLAC__byte*)chunk_id, e->format==FORMAT_WAVE64?16:4, /*eof_ok=*/true, e->inbasefilename)) {
			flac__utils_printf(stderr, 1, "%s: ERROR: incomplete chunk identifier\n", e->inbasefilename);
			return false;
		}
		if(feof(e->fin))
			break;

		if(e->format == FORMAT_RF64 && !memcmp(chunk_id, "ds64", 4)) { /* RF64 64-bit sizes chunk */
			FLAC__uint32 xx, data_bytes;

			if(got_ds64_chunk) {
				flac__utils_printf(stderr, 1, "%s: ERROR: file has multiple 'ds64' chunks\n", e->inbasefilename);
				return false;
			}
			if(got_fmt_chunk || got_data_chunk) {
				flac__utils_printf(stderr, 1, "%s: ERROR: 'ds64' chunk appears after 'fmt ' or 'data' chunk\n", e->inbasefilename);
				return false;
			}

			/* ds64 chunk size */
			if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
				return false;
			data_bytes = xx;
			if(data_bytes < 28) {
				flac__utils_printf(stderr, 1, "%s: ERROR: non-standard 'ds64' chunk has length = %u\n", e->inbasefilename, (unsigned)data_bytes);
				return false;
			}
			if(data_bytes & 1) /* should never happen, but enforce WAVE alignment rules */
				data_bytes++;

			/* RIFF 64-bit size, lo/hi */
			if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
				return false;
			if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
				return false;

			/* 'data' 64-bit size */
			if(!read_uint64(e->fin, /*big_endian=*/false, &ds64_data_size, e->inbasefilename))
				return false;

			data_bytes -= 16;

			/* skip any extra data in the ds64 chunk */
			if(!fskip_ahead(e->fin, data_bytes)) {
				flac__utils_printf(stderr, 1, "%s: ERROR during read while skipping over extra 'ds64' data\n", e->inbasefilename);
				return false;
			}

			got_ds64_chunk = true;
		}
		else if(
			!memcmp(chunk_id, "fmt ", 4) &&
			(e->format!=FORMAT_WAVE64 || !memcmp(chunk_id, "fmt \xF3\xAC\xD3\x11\x8C\xD1\x00\xC0\x4F\x8E\xDB\x8A", 16))
		) { /* format chunk */
			FLAC__uint16 x;
			FLAC__uint32 xx, data_bytes;
			FLAC__uint16 wFormatTag; /* wFormatTag word from the 'fmt ' chunk */

			if(got_fmt_chunk) {
				flac__utils_printf(stderr, 1, "%s: ERROR: file has multiple 'fmt ' chunks\n", e->inbasefilename);
				return false;
			}

			/* see
			 *   http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html
			 *   http://windowssdk.msdn.microsoft.com/en-us/library/ms713497.aspx
			 *   http://msdn.microsoft.com/library/default.asp?url=/library/en-us/audio_r/hh/Audio_r/aud-prop_d40f094e-44f9-4baa-8a15-03e4fb369501.xml.asp
			 *
			 * WAVEFORMAT is
			 * 4 byte: chunk size
			 * 2 byte: format type: 1 for WAVE_FORMAT_PCM, 65534 for WAVE_FORMAT_EXTENSIBLE
			 * 2 byte: # channels
			 * 4 byte: sample rate (Hz)
			 * 4 byte: avg bytes per sec
			 * 2 byte: block align
			 * 2 byte: bits per sample (not necessarily all significant)
			 * WAVEFORMATEX adds
			 * 2 byte: extension size in bytes (usually 0 for WAVEFORMATEX and 22 for WAVEFORMATEXTENSIBLE with PCM)
			 * WAVEFORMATEXTENSIBLE adds
			 * 2 byte: valid bits per sample
			 * 4 byte: channel mask
			 * 16 byte: subformat GUID, first 2 bytes have format type, 1 being PCM
			 *
			 * Current spec says WAVEFORMATEX with PCM must have bps == 8 or 16, or any multiple of 8 for WAVEFORMATEXTENSIBLE.
			 * Lots of old broken WAVEs/apps have don't follow it, e.g. 20 bps but a block align of 3/6 for mono/stereo.
			 *
			 * Block align for WAVE_FORMAT_PCM or WAVE_FORMAT_EXTENSIBLE is also supposed to be channels*bps/8
			 *
			 * If the channel mask has more set bits than # of channels, the extra MSBs are ignored.
			 * If the channel mask has less set bits than # of channels, the extra channels are unassigned to any speaker.
			 *
			 * Data is supposed to be unsigned for bps <= 8 else signed.
			 */

			/* fmt chunk size */
			if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
				return false;
			data_bytes = xx;
			if(e->format == FORMAT_WAVE64) {
				/* other half of the size field should be 0 */
				if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
					return false;
				if(xx) {
					flac__utils_printf(stderr, 1, "%s: ERROR: freakishly large Wave64 'fmt ' chunk has length = 0x%08X%08X\n", e->inbasefilename, (unsigned)xx, (unsigned)data_bytes);
					return false;
				}
				/* subtract size of header */
				if (data_bytes < 16+8) {
					flac__utils_printf(stderr, 1, "%s: ERROR: freakishly small Wave64 'fmt ' chunk has length = 0x%08X%08X\n", e->inbasefilename, (unsigned)xx, (unsigned)data_bytes);
					return false;
				}
				data_bytes -= (16+8);
			}
			if(data_bytes < 16) {
				flac__utils_printf(stderr, 1, "%s: ERROR: non-standard 'fmt ' chunk has length = %u\n", e->inbasefilename, (unsigned)data_bytes);
				return false;
			}
			if(e->format != FORMAT_WAVE64) {
				if(data_bytes & 1) /* should never happen, but enforce WAVE alignment rules */
					data_bytes++;
			}
			else { /* Wave64 */
				data_bytes = (data_bytes+7) & (~7u); /* should never happen, but enforce Wave64 alignment rules */
			}

			/* format code */
			if(!read_uint16(e->fin, /*big_endian=*/false, &wFormatTag, e->inbasefilename))
				return false;
			if(wFormatTag != 1 /*WAVE_FORMAT_PCM*/ && wFormatTag != 65534 /*WAVE_FORMAT_EXTENSIBLE*/) {
				flac__utils_printf(stderr, 1, "%s: ERROR: unsupported format type %u\n", e->inbasefilename, (unsigned)wFormatTag);
				return false;
			}

			/* number of channels */
			if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
				return false;
			channels = (unsigned)x;

			/* sample rate */
			if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
				return false;
			sample_rate = xx;

			/* avg bytes per second (ignored) */
			if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
				return false;
			/* block align */
			if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
				return false;

			/* bits per sample */
			if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
				return false;
			bps = (unsigned)x;

			e->info.is_unsigned_samples = (bps <= 8);

			if(wFormatTag == 1) {
				if(bps != 8 && bps != 16) {
					if(bps == 24 || bps == 32) {
						/* let these slide with a warning since they're unambiguous */
						flac__utils_printf(stderr, 1, "%s: WARNING: legacy WAVE file has format type %u but bits-per-sample=%u\n", e->inbasefilename, (unsigned)wFormatTag, bps);
						if(e->treat_warnings_as_errors)
							return false;
					}
					else {
						/* @@@ we could add an option to specify left- or right-justified blocks so we knew how to set 'shift' */
						flac__utils_printf(stderr, 1, "%s: ERROR: legacy WAVE file has format type %u but bits-per-sample=%u\n", e->inbasefilename, (unsigned)wFormatTag, bps);
						return false;
					}
				}
#if 0 /* @@@ reinstate once we can get an answer about whether the samples are left- or right-justified */
				if((bps+7)/8 * channels == block_align) {
					if(bps % 8) {
						/* assume legacy file is byte aligned with some LSBs zero; this is double-checked in format_input() */
						flac__utils_printf(stderr, 1, "%s: WARNING: legacy WAVE file (format type %d) has block alignment=%u, bits-per-sample=%u, channels=%u\n", e->inbasefilename, (unsigned)wFormatTag, block_align, bps, channels);
						if(e->treat_warnings_as_errors)
							return false;
						shift = 8 - (bps % 8);
						bps += shift;
					}
					else
						shift = 0;
				}
				else {
					flac__utils_printf(stderr, 1, "%s: ERROR: illegal WAVE file (format type %d) has block alignment=%u, bits-per-sample=%u, channels=%u\n", e->inbasefilename, (unsigned)wFormatTag, block_align, bps, channels);
					return false;
				}
#else
				shift = 0;
#endif
				if(channels > 2 && !options.channel_map_none) {
					flac__utils_printf(stderr, 1, "%s: ERROR: WAVE has >2 channels but is not WAVE_FORMAT_EXTENSIBLE; cannot assign channels\n", e->inbasefilename);
					return false;
				}
				FLAC__ASSERT(data_bytes >= 16);
				data_bytes -= 16;
			}
			else {
				if(data_bytes < 40) {
					flac__utils_printf(stderr, 1, "%s: ERROR: invalid WAVEFORMATEXTENSIBLE chunk with size %u\n", e->inbasefilename, (unsigned)data_bytes);
					return false;
				}
				/* cbSize */
				if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
					return false;
				if(x < 22) {
					flac__utils_printf(stderr, 1, "%s: ERROR: invalid WAVEFORMATEXTENSIBLE chunk with cbSize %u\n", e->inbasefilename, (unsigned)x);
					return false;
				}
				/* valid bps */
				if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
					return false;
				if((unsigned)x > bps) {
					flac__utils_printf(stderr, 1, "%s: ERROR: invalid WAVEFORMATEXTENSIBLE chunk with wValidBitsPerSample (%u) > wBitsPerSample (%u)\n", e->inbasefilename, (unsigned)x, bps);
					return false;
				}
				shift = bps - (unsigned)x;
				/* channel mask */
				if(!read_uint32(e->fin, /*big_endian=*/false, &channel_mask, e->inbasefilename))
					return false;
				/* for mono/stereo and unassigned channels, we fake the mask */
				if(channel_mask == 0) {
					if(channels == 1)
						channel_mask = 0x0001;
					else if(channels == 2)
						channel_mask = 0x0003;
				}
				/* set channel mapping */
				/* FLAC order follows SMPTE and WAVEFORMATEXTENSIBLE but with fewer channels, which are: */
				/* front left, front right, center, LFE, back left, back right, surround left, surround right */
				/* the default mapping is sufficient for 1-6 channels and 7-8 are currently unspecified anyway */
#if 0
				/* @@@ example for dolby/vorbis order, for reference later in case it becomes important */
				if(
					options.channel_map_none ||
					channel_mask == 0x0001 || /* 1 channel: (mono) */
					channel_mask == 0x0003 || /* 2 channels: front left, front right */
					channel_mask == 0x0033 || /* 4 channels: front left, front right, back left, back right */
					channel_mask == 0x0603    /* 4 channels: front left, front right, side left, side right */
				) {
					/* keep default channel order */
				}
				else if(
					channel_mask == 0x0007 || /* 3 channels: front left, front right, front center */
					channel_mask == 0x0037 || /* 5 channels: front left, front right, front center, back left, back right */
					channel_mask == 0x0607    /* 5 channels: front left, front right, front center, side left, side right */
				) {
					/* to dolby order: front left, center, front right [, surround left, surround right ] */
					channel_map[1] = 2;
					channel_map[2] = 1;
				}
				else if(
					channel_mask == 0x003f || /* 6 channels: front left, front right, front center, LFE, back left, back right */
					channel_mask == 0x060f || /* 6 channels: front left, front right, front center, LFE, side left, side right */
					channel_mask == 0x070f || /* 7 channels: front left, front right, front center, LFE, back center, side left, side right */
					channel_mask == 0x063f    /* 8 channels: front left, front right, front center, LFE, back left, back right, side left, side right */
				) {
					/* to dolby order: front left, center, front right, surround left, surround right, LFE */
					channel_map[1] = 2;
					channel_map[2] = 1;
					channel_map[3] = 5;
					channel_map[4] = 3;
					channel_map[5] = 4;
				}
#else
				if(
					options.channel_map_none ||
					channel_mask == 0x0001 || /* 1 channel: (mono) */
					channel_mask == 0x0003 || /* 2 channels: front left, front right */
					channel_mask == 0x0007 || /* 3 channels: front left, front right, front center */
					channel_mask == 0x0033 || /* 4 channels: front left, front right, back left, back right */
					channel_mask == 0x0603 || /* 4 channels: front left, front right, side left, side right */
					channel_mask == 0x0037 || /* 5 channels: front left, front right, front center, back left, back right */
					channel_mask == 0x0607 || /* 5 channels: front left, front right, front center, side left, side right */
					channel_mask == 0x003f || /* 6 channels: front left, front right, front center, LFE, back left, back right */
					channel_mask == 0x060f || /* 6 channels: front left, front right, front center, LFE, side left, side right */
					channel_mask == 0x070f || /* 7 channels: front left, front right, front center, LFE, back center, side left, side right */
					channel_mask == 0x063f    /* 8 channels: front left, front right, front center, LFE, back left, back right, side left, side right */
				) {
					/* keep default channel order */
				}
#endif
				else {
					flac__utils_printf(stderr, 1, "%s: ERROR: WAVEFORMATEXTENSIBLE chunk with unsupported channel mask=0x%04X\n\nUse --channel-map=none option to store channels in current order; FLAC files\nmust also be decoded with --channel-map=none to restore correct order.\n", e->inbasefilename, (unsigned)channel_mask);
					return false;
				}
				if(!options.channel_map_none) {
					if(count_channel_mask_bits(channel_mask) < channels) {
						flac__utils_printf(stderr, 1, "%s: ERROR: WAVEFORMATEXTENSIBLE chunk: channel mask 0x%04X has unassigned channels (#channels=%u)\n", e->inbasefilename, (unsigned)channel_mask, channels);
						return false;
					}
#if 0
					/* supporting this is too difficult with channel mapping; e.g. what if mask is 0x003f but #channels=4?
					 * there would be holes in the order that would have to be filled in, or the mask would have to be
					 * limited and the logic above rerun to see if it still fits into the FLAC mapping.
					 */
					else if(count_channel_mask_bits(channel_mask) > channels)
						channel_mask = limit_channel_mask(channel_mask, channels);
#else
					else if(count_channel_mask_bits(channel_mask) > channels) {
						flac__utils_printf(stderr, 1, "%s: ERROR: WAVEFORMATEXTENSIBLE chunk: channel mask 0x%04X has extra bits for non-existant channels (#channels=%u)\n", e->inbasefilename, (unsigned)channel_mask, channels);
						return false;
					}
#endif
				}
				/* first part of GUID */
				if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
					return false;
				if(x != 1) {
					flac__utils_printf(stderr, 1, "%s: ERROR: unsupported WAVEFORMATEXTENSIBLE chunk with non-PCM format %u\n", e->inbasefilename, (unsigned)x);
					return false;
				}
				data_bytes -= 26;
			}

			e->info.bytes_per_wide_sample = channels * (bps / 8);

			/* skip any extra data in the fmt chunk */
			if(!fskip_ahead(e->fin, data_bytes)) {
				flac__utils_printf(stderr, 1, "%s: ERROR during read while skipping over extra 'fmt' data\n", e->inbasefilename);
				return false;
			}

			got_fmt_chunk = true;
		}
		else if(
			!memcmp(chunk_id, "data", 4) &&
			(e->format!=FORMAT_WAVE64 || !memcmp(chunk_id, "data\xF3\xAC\xD3\x11\x8C\xD1\x00\xC0\x4F\x8E\xDB\x8A", 16))
		) { /* data chunk */
			FLAC__uint32 xx;
			FLAC__uint64 data_bytes;

			if(!got_fmt_chunk) {
				flac__utils_printf(stderr, 1, "%s: ERROR: got 'data' chunk before 'fmt' chunk\n", e->inbasefilename);
				return false;
			}

			/* data size */
			if(e->format != FORMAT_WAVE64) {
				if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
					return false;
				data_bytes = xx;
			}
			else { /* Wave64 */
				if(!read_uint64(e->fin, /*big_endian=*/false, &data_bytes, e->inbasefilename))
					return false;
				/* subtract size of header */
				if (data_bytes < 16+8) {
					flac__utils_printf(stderr, 1, "%s: ERROR: freakishly small Wave64 'data' chunk has length = 0x00000000%08X\n", e->inbasefilename, (unsigned)data_bytes);
					return false;
				}
				data_bytes -= (16+8);
			}
			if(e->format == FORMAT_RF64) {
				if(!got_ds64_chunk) {
					flac__utils_printf(stderr, 1, "%s: ERROR: RF64 file has no 'ds64' chunk before 'data' chunk\n", e->inbasefilename);
					return false;
				}
				if(data_bytes == 0xffffffff)
					data_bytes = ds64_data_size;
			}
			if(options.ignore_chunk_sizes) {
				FLAC__ASSERT(!options.sector_align);
				if(data_bytes) {
					flac__utils_printf(stderr, 1, "%s: WARNING: 'data' chunk has non-zero size, using --ignore-chunk-sizes is probably a bad idea\n", e->inbasefilename, chunk_id);
					if(e->treat_warnings_as_errors)
						return false;
				}
				data_bytes = (FLAC__uint64)0 - (FLAC__uint64)e->info.bytes_per_wide_sample; /* max out data_bytes; we'll use EOF as signal to stop reading */
			}
			else if(0 == data_bytes) {
				flac__utils_printf(stderr, 1, "%s: ERROR: 'data' chunk has size of 0\n", e->inbasefilename);
				return false;
			}

			e->fmt.iff.data_bytes = data_bytes;

			got_data_chunk = true;
			break;
		}
		else {
			FLAC__uint32 xx;
			FLAC__uint64 skip;
			if(!options.format_options.iff.foreign_metadata) {
				if(e->format != FORMAT_WAVE64)
					flac__utils_printf(stderr, 1, "%s: WARNING: skipping unknown chunk '%s' (use --keep-foreign-metadata to keep)\n", e->inbasefilename, chunk_id);
				else
					flac__utils_printf(stderr, 1, "%s: WARNING: skipping unknown chunk %02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X (use --keep-foreign-metadata to keep)\n",
						e->inbasefilename,
						(unsigned)((const unsigned char *)chunk_id)[3],
						(unsigned)((const unsigned char *)chunk_id)[2],
						(unsigned)((const unsigned char *)chunk_id)[1],
						(unsigned)((const unsigned char *)chunk_id)[0],
						(unsigned)((const unsigned char *)chunk_id)[5],
						(unsigned)((const unsigned char *)chunk_id)[4],
						(unsigned)((const unsigned char *)chunk_id)[7],
						(unsigned)((const unsigned char *)chunk_id)[6],
						(unsigned)((const unsigned char *)chunk_id)[9],
						(unsigned)((const unsigned char *)chunk_id)[8],
						(unsigned)((const unsigned char *)chunk_id)[10],
						(unsigned)((const unsigned char *)chunk_id)[11],
						(unsigned)((const unsigned char *)chunk_id)[12],
						(unsigned)((const unsigned char *)chunk_id)[13],
						(unsigned)((const unsigned char *)chunk_id)[14],
						(unsigned)((const unsigned char *)chunk_id)[15]
					);
				if(e->treat_warnings_as_errors)
					return false;
			}

			/* chunk size */
			if(e->format != FORMAT_WAVE64) {
				if(!read_uint32(e->fin, /*big_endian=*/false, &xx, e->inbasefilename))
					return false;
				skip = xx;
				skip += skip & 1;
			}
			else { /* Wave64 */
				if(!read_uint64(e->fin, /*big_endian=*/false, &skip, e->inbasefilename))
					return false;
				skip = (skip+7) & (~(FLAC__uint64)7);
				/* subtract size of header */
				if (skip < 16+8) {
					flac__utils_printf(stderr, 1, "%s: ERROR: freakishly small Wave64 chunk has length = 0x00000000%08X\n", e->inbasefilename, (unsigned)skip);
					return false;
				}
				skip -= (16+8);
			}
			if(skip) {
				if(!fskip_ahead(e->fin, skip)) {
					flac__utils_printf(stderr, 1, "%s: ERROR during read while skipping over chunk\n", e->inbasefilename);
					return false;
				}
			}
		}
	}

	if(!got_fmt_chunk) {
		flac__utils_printf(stderr, 1, "%s: ERROR: didn't find fmt chunk\n", e->inbasefilename);
		return false;
	}
	if(!got_data_chunk) {
		flac__utils_printf(stderr, 1, "%s: ERROR: didn't find data chunk\n", e->inbasefilename);
		return false;
	}

	e->info.sample_rate = sample_rate;
	e->info.channels = channels;
	e->info.bits_per_sample = bps;
	e->info.shift = shift;
	e->info.channel_mask = channel_mask;

	return true;
}

static FLAC__bool get_sample_info_aiff(EncoderSession *e, encode_options_t options)
{
	FLAC__bool got_comm_chunk = false, got_ssnd_chunk = false;
	unsigned sample_rate = 0, channels = 0, bps = 0, shift = 0;
	FLAC__uint64 sample_frames = 0;
	FLAC__uint32 channel_mask = 0;

	e->info.is_unsigned_samples = false;
	e->info.is_big_endian = true;

	/*
	 * lookahead[] already has "FORMxxxxAIFF", do chunks
	 */
	while(!feof(e->fin) && !got_ssnd_chunk) {
		char chunk_id[5] = { '\0', '\0', '\0', '\0', '\0' }; /* one extra byte for terminating NUL so we can also treat it like a C string */
		if(!read_bytes(e->fin, (FLAC__byte*)chunk_id, 4, /*eof_ok=*/true, e->inbasefilename)) {
			flac__utils_printf(stderr, 1, "%s: ERROR: incomplete chunk identifier\n", e->inbasefilename);
			return false;
		}
		if(feof(e->fin))
			break;

		if(!memcmp(chunk_id, "COMM", 4)) { /* common chunk */
			FLAC__uint16 x;
			FLAC__uint32 xx;
			unsigned long skip;
			const FLAC__bool is_aifc = e->format == FORMAT_AIFF_C;
			const FLAC__uint32 minimum_comm_size = (is_aifc? 22 : 18);

			if(got_comm_chunk) {
				flac__utils_printf(stderr, 1, "%s: ERROR: file has multiple 'COMM' chunks\n", e->inbasefilename);
				return false;
			}

			/* COMM chunk size */
			if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
				return false;
			else if(xx < minimum_comm_size) {
				flac__utils_printf(stderr, 1, "%s: ERROR: non-standard %s 'COMM' chunk has length = %u\n", e->inbasefilename, is_aifc? "AIFF-C" : "AIFF", (unsigned int)xx);
				return false;
			}
			else if(!is_aifc && xx != minimum_comm_size) {
				flac__utils_printf(stderr, 1, "%s: WARNING: non-standard %s 'COMM' chunk has length = %u, expected %u\n", e->inbasefilename, is_aifc? "AIFF-C" : "AIFF", (unsigned int)xx, minimum_comm_size);
				if(e->treat_warnings_as_errors)
					return false;
			}
			skip = (xx-minimum_comm_size)+(xx & 1);

			/* number of channels */
			if(!read_uint16(e->fin, /*big_endian=*/true, &x, e->inbasefilename))
				return false;
			channels = (unsigned)x;
			if(channels > 2 && !options.channel_map_none) {
				flac__utils_printf(stderr, 1, "%s: ERROR: unsupported number of channels %u for AIFF\n", e->inbasefilename, channels);
				return false;
			}

			/* number of sample frames */
			if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
				return false;
			sample_frames = xx;

			/* bits per sample */
			if(!read_uint16(e->fin, /*big_endian=*/true, &x, e->inbasefilename))
				return false;
			bps = (unsigned)x;
			shift = (bps%8)? 8-(bps%8) : 0; /* SSND data is always byte-aligned, left-justified but format_input() will double-check */
			bps += shift;

			/* sample rate */
			if(!read_sane_extended(e->fin, &xx, e->inbasefilename))
				return false;
			sample_rate = xx;

			/* check compression type for AIFF-C */
			if(is_aifc) {
				if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
					return false;
				if(xx == 0x736F7774) /* "sowt" */
					e->info.is_big_endian = false;
				else if(xx == 0x4E4F4E45) /* "NONE" */
					; /* nothing to do, we already default to big-endian */
				else {
					flac__utils_printf(stderr, 1, "%s: ERROR: can't handle AIFF-C compression type \"%c%c%c%c\"\n", e->inbasefilename, (char)(xx>>24), (char)((xx>>16)&8), (char)((xx>>8)&8), (char)(xx&8));
					return false;
				}
			}

			/* set channel mapping */
			/* FLAC order follows SMPTE and WAVEFORMATEXTENSIBLE but with fewer channels, which are: */
			/* front left, front right, center, LFE, back left, back right, surround left, surround right */
			/* specs say the channel ordering is:
			 *                             1     2   3   4   5   6
			 * ___________________________________________________
			 * 2         stereo            l     r
			 * 3                           l     r   c
			 * 4                           l     c   r   S
			 * quad (ambiguous with 4ch)  Fl    Fr   Bl  Br
			 * 5                          Fl     Fr  Fc  Sl  Sr
			 * 6                           l     lc  c   r   rc  S
			 * l:left r:right c:center Fl:front-left Fr:front-right Bl:back-left Br:back-right Lc:left-center Rc:right-center S:surround
			 * so we only have unambiguous mappings for 2, 3, and 5 channels
			 */
			if(
				options.channel_map_none ||
				channels == 1 || /* 1 channel: (mono) */
				channels == 2 || /* 2 channels: left, right */
				channels == 3 || /* 3 channels: left, right, center */
				channels == 5    /* 5 channels: front left, front right, center, surround left, surround right */
			) {
				/* keep default channel order */
			}
			else {
				flac__utils_printf(stderr, 1, "%s: ERROR: unsupported number of channels %u for AIFF\n", e->inbasefilename, channels);
				return false;
			}

			e->info.bytes_per_wide_sample = channels * (bps / 8);

			/* skip any extra data in the COMM chunk */
			if(!fskip_ahead(e->fin, skip)) {
				flac__utils_printf(stderr, 1, "%s: ERROR during read while skipping over extra COMM data\n", e->inbasefilename);
				return false;
			}

			got_comm_chunk = true;
		}
		else if(!memcmp(chunk_id, "SSND", 4) && !got_ssnd_chunk) { /* sound data chunk */
			FLAC__uint32 xx;
			FLAC__uint64 data_bytes;
			unsigned offset = 0;

			if(!got_comm_chunk) {
				flac__utils_printf(stderr, 1, "%s: ERROR: got 'SSND' chunk before 'COMM' chunk\n", e->inbasefilename);
				return false;
			}

			/* SSND chunk size */
			if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
				return false;
			data_bytes = xx;
			if(options.ignore_chunk_sizes) {
				FLAC__ASSERT(!options.sector_align);
				if(data_bytes) {
					flac__utils_printf(stderr, 1, "%s: WARNING: 'SSND' chunk has non-zero size, using --ignore-chunk-sizes is probably a bad idea\n", e->inbasefilename, chunk_id);
					if(e->treat_warnings_as_errors)
						return false;
				}
				data_bytes = (FLAC__uint64)0 - (FLAC__uint64)e->info.bytes_per_wide_sample; /* max out data_bytes; we'll use EOF as signal to stop reading */
			}
			else if(data_bytes <= 8) {
				flac__utils_printf(stderr, 1, "%s: ERROR: 'SSND' chunk has size <= 8\n", e->inbasefilename);
				return false;
			}
			else {
				data_bytes -= 8; /* discount the offset and block size fields */
			}

			/* offset */
			if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
				return false;
			offset = xx;
			data_bytes -= offset;

			/* block size */
			if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
				return false;
			if(xx && !options.ignore_chunk_sizes)
				data_bytes -= (xx - (data_bytes % xx));
			if(options.ignore_chunk_sizes) {
				if(xx) {
					flac__utils_printf(stderr, 1, "%s: WARNING: 'SSND' chunk has non-zero blocksize, using --ignore-chunk-sizes is probably a bad idea\n", e->inbasefilename, chunk_id);
					if(e->treat_warnings_as_errors)
						return false;
				}
			}

			/* skip any SSND offset bytes */
			if(!fskip_ahead(e->fin, offset)) {
				flac__utils_printf(stderr, 1, "%s: ERROR: skipping offset in SSND chunk\n", e->inbasefilename);
				return false;
			}

			e->fmt.iff.data_bytes = data_bytes;

			got_ssnd_chunk = true;
		}
		else {
			FLAC__uint32 xx;
			if(!options.format_options.iff.foreign_metadata) {
				flac__utils_printf(stderr, 1, "%s: WARNING: skipping unknown chunk '%s' (use --keep-foreign-metadata to keep)\n", e->inbasefilename, chunk_id);
				if(e->treat_warnings_as_errors)
					return false;
			}

			/* chunk size */
			if(!read_uint32(e->fin, /*big_endian=*/true, &xx, e->inbasefilename))
				return false;
			else {
				unsigned long skip = xx + (xx & 1);

				FLAC__ASSERT(skip <= LONG_MAX);
				if(!fskip_ahead(e->fin, skip)) {
					flac__utils_printf(stderr, 1, "%s: ERROR during read while skipping over chunk\n", e->inbasefilename);
					return false;
				}
			}
		}
	}

	if(!got_comm_chunk) {
		flac__utils_printf(stderr, 1, "%s: ERROR: didn't find COMM chunk\n", e->inbasefilename);
		return false;
	}
	if(!got_ssnd_chunk && sample_frames) {
		flac__utils_printf(stderr, 1, "%s: ERROR: didn't find SSND chunk\n", e->inbasefilename);
		return false;
	}

	e->info.sample_rate = sample_rate;
	e->info.channels = channels;
	e->info.bits_per_sample = bps;
	e->info.shift = shift;
	e->info.channel_mask = channel_mask;

	return true;
}

static FLAC__bool get_sample_info_flac(EncoderSession *e)
{
	if (!(
		FLAC__stream_decoder_set_md5_checking(e->fmt.flac.decoder, false) &&
		FLAC__stream_decoder_set_metadata_respond_all(e->fmt.flac.decoder)
	)) {
		flac__utils_printf(stderr, 1, "%s: ERROR: setting up decoder for FLAC input\n", e->inbasefilename);
		return false;
	}

	if (e->format == FORMAT_OGGFLAC) {
		if (FLAC__stream_decoder_init_ogg_stream(e->fmt.flac.decoder, flac_decoder_read_callback, flac_decoder_seek_callback, flac_decoder_tell_callback, flac_decoder_length_callback, flac_decoder_eof_callback, flac_decoder_write_callback, flac_decoder_metadata_callback, flac_decoder_error_callback, /*client_data=*/e) != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
			flac__utils_printf(stderr, 1, "%s: ERROR: initializing decoder for Ogg FLAC input, state = %s\n", e->inbasefilename, FLAC__stream_decoder_get_resolved_state_string(e->fmt.flac.decoder));
			return false;
		}
	}
	else if (FLAC__stream_decoder_init_stream(e->fmt.flac.decoder, flac_decoder_read_callback, flac_decoder_seek_callback, flac_decoder_tell_callback, flac_decoder_length_callback, flac_decoder_eof_callback, flac_decoder_write_callback, flac_decoder_metadata_callback, flac_decoder_error_callback, /*client_data=*/e) != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
		flac__utils_printf(stderr, 1, "%s: ERROR: initializing decoder for FLAC input, state = %s\n", e->inbasefilename, FLAC__stream_decoder_get_resolved_state_string(e->fmt.flac.decoder));
		return false;
	}

	if (!FLAC__stream_decoder_process_until_end_of_metadata(e->fmt.flac.decoder) || e->fmt.flac.client_data.fatal_error) {
		if (e->fmt.flac.client_data.fatal_error)
			flac__utils_printf(stderr, 1, "%s: ERROR: out of memory or too many metadata blocks while reading metadata in FLAC input\n", e->inbasefilename);
		else
			flac__utils_printf(stderr, 1, "%s: ERROR: reading metadata in FLAC input, state = %s\n", e->inbasefilename, FLAC__stream_decoder_get_resolved_state_string(e->fmt.flac.decoder));
		return false;
	}

	if (e->fmt.flac.client_data.num_metadata_blocks == 0) {
		flac__utils_printf(stderr, 1, "%s: ERROR: reading metadata in FLAC input, got no metadata blocks\n", e->inbasefilename);
		return false;
	}
	else if (e->fmt.flac.client_data.metadata_blocks[0]->type != FLAC__METADATA_TYPE_STREAMINFO) {
		flac__utils_printf(stderr, 1, "%s: ERROR: reading metadata in FLAC input, first metadata block is not STREAMINFO\n", e->inbasefilename);
		return false;
	}
	else if (e->fmt.flac.client_data.metadata_blocks[0]->data.stream_info.total_samples == 0) {
		flac__utils_printf(stderr, 1, "%s: ERROR: FLAC input has STREAMINFO with unknown total samples which is not supported\n", e->inbasefilename);
		return false;
	}

	e->info.sample_rate = e->fmt.flac.client_data.metadata_blocks[0]->data.stream_info.sample_rate;
	e->info.channels = e->fmt.flac.client_data.metadata_blocks[0]->data.stream_info.channels;
	e->info.bits_per_sample = e->fmt.flac.client_data.metadata_blocks[0]->data.stream_info.bits_per_sample;
	e->info.shift = 0;
	e->info.bytes_per_wide_sample = 0;
	e->info.is_unsigned_samples = false; /* not applicable for FLAC input */
	e->info.is_big_endian = false; /* not applicable for FLAC input */
	e->info.channel_mask = 0;

	return true;
}

/*
 * public routines
 */
int flac__encode_file(FILE *infile, FLAC__off_t infilesize, const char *infilename, const char *outfilename, const FLAC__byte *lookahead, unsigned lookahead_length, encode_options_t options)
{
	EncoderSession encoder_session;
	size_t channel_map[FLAC__MAX_CHANNELS];
	int info_align_carry = -1, info_align_zero = -1;

	if(!EncoderSession_construct(&encoder_session, options, infilesize, infile, infilename, outfilename, lookahead, lookahead_length))
		return 1;

	/* initialize default channel map that preserves channel order */
	{
		size_t i;
		for(i = 0; i < sizeof(channel_map)/sizeof(channel_map[0]); i++)
			channel_map[i] = i;
	}

	/* read foreign metadata if requested */
	if(EncoderSession_format_is_iff(&encoder_session) && options.format_options.iff.foreign_metadata) {
		const char *error;
		if(!(
			options.format == FORMAT_WAVE || options.format == FORMAT_RF64?
				flac__foreign_metadata_read_from_wave(options.format_options.iff.foreign_metadata, infilename, &error) :
			options.format == FORMAT_WAVE64?
				flac__foreign_metadata_read_from_wave64(options.format_options.iff.foreign_metadata, infilename, &error) :
				flac__foreign_metadata_read_from_aiff(options.format_options.iff.foreign_metadata, infilename, &error)
		)) {
			flac__utils_printf(stderr, 1, "%s: ERROR reading foreign metadata: %s\n", encoder_session.inbasefilename, error);
			return EncoderSession_finish_error(&encoder_session);
		}
	}

	/* initialize encoder session with info about the audio (channels/bps/resolution/endianness/etc) */
	switch(options.format) {
		case FORMAT_RAW:
			if(!get_sample_info_raw(&encoder_session, options))
				return EncoderSession_finish_error(&encoder_session);
			break;
		case FORMAT_WAVE:
		case FORMAT_WAVE64:
		case FORMAT_RF64:
			if(!get_sample_info_wave(&encoder_session, options))
				return EncoderSession_finish_error(&encoder_session);
			break;
		case FORMAT_AIFF:
		case FORMAT_AIFF_C:
			if(!get_sample_info_aiff(&encoder_session, options))
				return EncoderSession_finish_error(&encoder_session);
			break;
		case FORMAT_FLAC:
		case FORMAT_OGGFLAC:
			/*
			 * set up FLAC decoder for the input
			 */
			if (0 == (encoder_session.fmt.flac.decoder = FLAC__stream_decoder_new())) {
				flac__utils_printf(stderr, 1, "%s: ERROR: creating decoder for FLAC input\n", encoder_session.inbasefilename);
				return EncoderSession_finish_error(&encoder_session);
			}
			if(!get_sample_info_flac(&encoder_session))
				return EncoderSession_finish_error(&encoder_session);
			break;
		default:
			FLAC__ASSERT(0);
			/* double protection */
			return EncoderSession_finish_error(&encoder_session);
	}

	/* some more checks */
	if(encoder_session.info.channels == 0 || encoder_session.info.channels > FLAC__MAX_CHANNELS) {
		flac__utils_printf(stderr, 1, "%s: ERROR: unsupported number of channels %u\n", encoder_session.inbasefilename, encoder_session.info.channels);
		return EncoderSession_finish_error(&encoder_session);
	}
	if(!FLAC__format_sample_rate_is_valid(encoder_session.info.sample_rate)) {
		flac__utils_printf(stderr, 1, "%s: ERROR: unsupported sample rate %u\n", encoder_session.inbasefilename, encoder_session.info.sample_rate);
		return EncoderSession_finish_error(&encoder_session);
	}
	if(encoder_session.info.bits_per_sample-encoder_session.info.shift < 4 || encoder_session.info.bits_per_sample-encoder_session.info.shift > 24) {
		flac__utils_printf(stderr, 1, "%s: ERROR: unsupported bits-per-sample %u\n", encoder_session.inbasefilename, encoder_session.info.bits_per_sample-encoder_session.info.shift);
		return EncoderSession_finish_error(&encoder_session);
	}
	if(options.sector_align) {
		if(encoder_session.info.channels != 2) {
			flac__utils_printf(stderr, 1, "%s: ERROR: file has %u channels, must be 2 for --sector-align\n", encoder_session.inbasefilename, encoder_session.info.channels);
			return EncoderSession_finish_error(&encoder_session);
		}
		if(encoder_session.info.sample_rate != 44100) {
			flac__utils_printf(stderr, 1, "%s: ERROR: file's sample rate is %u, must be 44100 for --sector-align\n", encoder_session.inbasefilename, encoder_session.info.sample_rate);
			return EncoderSession_finish_error(&encoder_session);
		}
		if(encoder_session.info.bits_per_sample-encoder_session.info.shift != 16) {
			flac__utils_printf(stderr, 1, "%s: ERROR: file has %u bits-per-sample, must be 16 for --sector-align\n", encoder_session.inbasefilename, encoder_session.info.bits_per_sample-encoder_session.info.shift);
			return EncoderSession_finish_error(&encoder_session);
		}
	}

	{
		FLAC__uint64 total_samples_in_input; /* WATCHOUT: may be 0 to mean "unknown" */
		FLAC__uint64 skip;
		FLAC__uint64 until; /* a value of 0 mean end-of-stream (i.e. --until=-0) */
		unsigned align_remainder = 0;

		switch(options.format) {
			case FORMAT_RAW:
				if(infilesize < 0)
					total_samples_in_input = 0;
				else
					total_samples_in_input = (FLAC__uint64)infilesize / encoder_session.info.bytes_per_wide_sample + *options.align_reservoir_samples;
				break;
			case FORMAT_WAVE:
			case FORMAT_WAVE64:
			case FORMAT_RF64:
			case FORMAT_AIFF:
			case FORMAT_AIFF_C:
				/* truncation in the division removes any padding byte that was counted in encoder_session.fmt.iff.data_bytes */
				total_samples_in_input = encoder_session.fmt.iff.data_bytes / encoder_session.info.bytes_per_wide_sample + *options.align_reservoir_samples;
				break;
			case FORMAT_FLAC:
			case FORMAT_OGGFLAC:
				total_samples_in_input = encoder_session.fmt.flac.client_data.metadata_blocks[0]->data.stream_info.total_samples + *options.align_reservoir_samples;
				break;
			default:
				FLAC__ASSERT(0);
				/* double protection */
				return EncoderSession_finish_error(&encoder_session);
		}

		/*
		 * now that we know the sample rate, canonicalize the
		 * --skip string to an absolute sample number:
		 */
		flac__utils_canonicalize_skip_until_specification(&options.skip_specification, encoder_session.info.sample_rate);
		FLAC__ASSERT(options.skip_specification.value.samples >= 0);
		skip = (FLAC__uint64)options.skip_specification.value.samples;
		FLAC__ASSERT(!options.sector_align || (options.format != FORMAT_FLAC && options.format != FORMAT_OGGFLAC && skip == 0));
		/* *options.align_reservoir_samples will be 0 unless --sector-align is used */
		FLAC__ASSERT(options.sector_align || *options.align_reservoir_samples == 0);

		/*
		 * now that we possibly know the input size, canonicalize the
		 * --until string to an absolute sample number:
		 */
		if(!canonicalize_until_specification(&options.until_specification, encoder_session.inbasefilename, encoder_session.info.sample_rate, skip, total_samples_in_input))
			return EncoderSession_finish_error(&encoder_session);
		until = (FLAC__uint64)options.until_specification.value.samples;
		FLAC__ASSERT(!options.sector_align || until == 0);

		/* adjust encoding parameters based on skip and until values */
		switch(options.format) {
			case FORMAT_RAW:
				infilesize -= (FLAC__off_t)skip * encoder_session.info.bytes_per_wide_sample;
				encoder_session.total_samples_to_encode = total_samples_in_input - skip;
				break;
			case FORMAT_WAVE:
			case FORMAT_WAVE64:
			case FORMAT_RF64:
			case FORMAT_AIFF:
			case FORMAT_AIFF_C:
				encoder_session.fmt.iff.data_bytes -= skip * encoder_session.info.bytes_per_wide_sample;
				if(options.ignore_chunk_sizes) {
					encoder_session.total_samples_to_encode = 0;
					flac__utils_printf(stderr, 2, "(No runtime statistics possible; please wait for encoding to finish...)\n");
					FLAC__ASSERT(0 == until);
				}
				else {
					encoder_session.total_samples_to_encode = total_samples_in_input - skip;
				}
				break;
			case FORMAT_FLAC:
			case FORMAT_OGGFLAC:
				encoder_session.total_samples_to_encode = total_samples_in_input - skip;
				break;
			default:
				FLAC__ASSERT(0);
				/* double protection */
				return EncoderSession_finish_error(&encoder_session);
		}
		if(until > 0) {
			const FLAC__uint64 trim = total_samples_in_input - until;