format_vorbis.c

/* format_vorbis.c
**
** format plugin for vorbis
**
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <ogg/ogg.h>
#include <vorbis/codec.h>

#include "refbuf.h"

#include "stats.h"
#include "format.h"

typedef struct _vstate_tag
{
	ogg_sync_state oy;
	ogg_stream_state os;
	vorbis_info vi;
	vorbis_comment vc;

	ogg_page og;
	unsigned long serialno;
	int header;
	refbuf_t *headbuf[10];
	int packets;
} vstate_t;

void format_vorbis_free_plugin(format_plugin_t *self);
refbuf_t *format_vorbis_get_buffer(format_plugin_t *self, char *data, unsigned long len);
refbuf_queue_t *format_vorbis_get_predata(format_plugin_t *self);

format_plugin_t *format_vorbis_get_plugin(void)
{
	format_plugin_t *plugin;
	vstate_t *state;

	plugin = (format_plugin_t *)malloc(sizeof(format_plugin_t));

	plugin->type = FORMAT_TYPE_VORBIS;
	plugin->has_predata = 1;
	plugin->get_buffer = format_vorbis_get_buffer;
	plugin->get_predata = format_vorbis_get_predata;
	plugin->free_plugin = format_vorbis_free_plugin;

	state = (vstate_t *)calloc(1, sizeof(vstate_t));
	ogg_sync_init(&state->oy);

	plugin->_state = (void *)state;

	return plugin;
}

void format_vorbis_free_plugin(format_plugin_t *self)
{
	int i;
	vstate_t *state = (vstate_t *)self->_state;

	/* free memory associated with this plugin instance */

	/* free state memory */
	ogg_sync_clear(&state->oy);
	ogg_stream_clear(&state->os);
	vorbis_comment_clear(&state->vc);
	vorbis_info_clear(&state->vi);
	
	for (i = 0; i < 10; i++) {
		if (state->headbuf[i]) {
			refbuf_release(state->headbuf[i]);
			state->headbuf[i] = NULL;
		}
	}

	free(state);

	/* free the plugin instance */
	free(self);
}

refbuf_t *format_vorbis_get_buffer(format_plugin_t *self, char *data, unsigned long len)
{
	char *buffer;
	refbuf_t *refbuf;
	int i, result;
	ogg_packet op;
	char *tag;
	vstate_t *state = (vstate_t *)self->_state;

	if (data) {
		/* write the data to the buffer */
		buffer = ogg_sync_buffer(&state->oy, len);
	        memcpy(buffer, data, len);
		ogg_sync_wrote(&state->oy, len);
	}

	refbuf = NULL;
	if (ogg_sync_pageout(&state->oy, &state->og) == 1) {
		refbuf = refbuf_new(state->og.header_len + state->og.body_len);
		memcpy(refbuf->data, state->og.header, state->og.header_len);
		memcpy(&refbuf->data[state->og.header_len], state->og.body, state->og.body_len);

		if (state->serialno != ogg_page_serialno(&state->og)) {
			/* this is a new logical bitstream */
			state->header = 0;
			state->packets = 0;

			/* release old headers, stream state, vorbis data */
			for (i = 0; i < 10; i++) {
				if (state->headbuf[i]) {
					refbuf_release(state->headbuf[i]);
					state->headbuf[i] = NULL;
				}
			}

			state->serialno = ogg_page_serialno(&state->og);
			ogg_stream_init(&state->os, state->serialno);
			vorbis_info_init(&state->vi);
			vorbis_comment_init(&state->vc);
		}

		if (state->header >= 0) {
            /* FIXME: In some streams (non-vorbis ogg streams), this could get
             * extras pages beyond the header. We need to collect the pages
             * here anyway, but they may have to be discarded later.
             */
			if (ogg_page_granulepos(&state->og) <= 0) {
				state->header++;
			} else {
				/* we're done caching headers */
				state->header = -1;

				/* put known comments in the stats */
				tag = vorbis_comment_query(&state->vc, "TITLE", 0);
				if (tag) stats_event_args(self->mount, "title", tag);
				else stats_event_args(self->mount, "title", "unknown");
				tag = vorbis_comment_query(&state->vc, "ARTIST", 0);
				if (tag) stats_event_args(self->mount, "artist", tag);
				else stats_event_args(self->mount, "artist", "unknown");

				/* don't need these now */
				ogg_stream_clear(&state->os);
				vorbis_comment_clear(&state->vc);
				vorbis_info_clear(&state->vi);
			}
		}

		/* cache header pages */
		if (state->header > 0) {
			refbuf_addref(refbuf);
			state->headbuf[state->header - 1] = refbuf;

			if (state->packets >= 0 && state->packets < 2) {
				ogg_stream_pagein(&state->os, &state->og);
				while (state->packets < 2) {
					result = ogg_stream_packetout(&state->os, &op);
					if (result == 0) break; /* need more data */
					if (result < 0) {
						state->packets = -1;
						break;
					}

					state->packets++;

					if (vorbis_synthesis_headerin(&state->vi, &state->vc, &op) < 0) {
						state->packets = -1;
						break;
					}
				}
			}
		}
	}

	return refbuf;
}

refbuf_queue_t *format_vorbis_get_predata(format_plugin_t *self)
{
	refbuf_queue_t *queue;
	int i;
	vstate_t *state = (vstate_t *)self->_state;

	queue = NULL;
	for (i = 0; i < 10; i++) {
		if (state->headbuf[i]) {
			refbuf_addref(state->headbuf[i]);
			refbuf_queue_add(&queue, state->headbuf[i]);
		} else {
			break;
		}
	}

	return queue;
}