diff --git a/COPYING b/COPYING
index e9705a5fe3fffa4f76af92f8d3dabde967f3a38c..5e54c85660b32dfb3be2e10bff7127a219e711b5 100644
--- a/COPYING
+++ b/COPYING
@@ -1,5 +1,5 @@
-Copyright 2005-2007 Christopher Montgomery, Jean-Marc Valin,
- Timothy Terriberry, CSIRO, and other contributors
+Copyright 2001-2009 Jean-Marc Valin, Timothy B. Terriberry,
+ CSIRO, and other contributors
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
diff --git a/README b/README
index b957da8847f6b1262b00225a65497a5480717148..73a2292af2a29f99eb5e86346cd0889d24a4dbbc 100644
--- a/README
+++ b/README
@@ -1,20 +1,88 @@
CELT is a very low delay audio codec designed for high-quality communications.
-Its potential uses include video-conferencing and network music performance.
-The code is still in early stage, so it may be broken from time to time and
+
+Traditional full-bandwidth codecs such as Vorbis and AAC can offer high
+quality but they require codec delays of hundreds of milliseconds, which
+makes them unsuitable for real-time interactive applications like tele-
+conferencing. Speech targeted codecs, such as Speex or G.722, have lower
+20-40ms delays but their speech focus and limited sampling rates
+restricts their quality, especially for music.
+
+Additionally, the other mandatory components of a full network audio system—
+audio interfaces, routers, jitter buffers— each add their own delay. For lower
+speed networks the time it takes to serialize a packet onto the network cable
+takes considerable time, and over the long distances the speed of light
+imposes a significant delay.
+
+In teleconferencing— it is important to keep delay low so that the participants
+can communicate fluidly without talking on top of each other and so that their
+own voices don't return after a round trip as an annoying echo.
+
+For network music performance— research has show that the total one way delay
+must be kept under 25ms to avoid degrading the musicians performance.
+
+Since many of the sources of delay in a complete system are outside of the
+user's control (such as the speed of light) it is often only possible to
+reduce the total delay by reducing the codec delay.
+
+Low delay has traditionally been considered a challenging area in audio codec
+design, because as a codec is forced to work on the smaller chunks of audio
+required for low delay it has access to less redundancy and less perceptual
+information which it can use to reduce the size of the transmitted audio.
+
+CELT is designed to bridge the gap between "music" and "speech" codecs,
+permitting new very high quality teleconferencing applications, and to go
+further, permitting latencies much lower than speech codecs normally provide
+to enable applications such as remote musical collaboration even over long
+distances.
+
+In keeping with the Xiph.Org mission— CELT is also designed to accomplish
+this without copyright or patent encumbrance. Only by keeping the formats
+that drive our Internet communication free and unencumbered can we maximize
+innovation, collaboration, and interoperability. Fortunately, CELT is ahead
+of the adoption curve in its target application space, so there should be
+no reason for someone who needs what CELT provides to go with a proprietary
+codec.
+
+CELT has been tested on x86, x86_64, ARM, and the TI C55x DSPs, and should
+be portable to any platform with a working C compiler and on the order of
+100 MIPS of processing power.
+
+The code is still in early stage, so it may be broken from time to time, and
the bit-stream is not frozen yet, so it is different from one version to
another. Oh, and don't complain if it sets your house on fire.
+Complaints and accolades can be directed to the CELT mailing list:
+http://lists.xiph.org/mailman/listinfo/celt-dev/
+
To compile:
% ./configure
% make
-To test the encoder:
+For platforms without fast floating point support (such as ARM) use the
+--enable-fixed argument to configure to build a fixed-point version of CELT.
+
+There are Ogg-based encode/decode tools in tools/. These are quite similar to
+the speexenc/speexdec tools. Use the --help option for details.
+
+There is also a basic tool for testing the encoder and decoder called
+"testcelt" located in libcelt/:
+
% testcelt <rate> <channels> <frame size> <bytes per packet> input.sw output.sw
-where input.sw is a 16-bit (machine endian) audio file sampled at
-44.1 kHz or 48 kHz. The output file is already decompressed.
-the <rate> parameter is the number of bytes per packet to use.
+where input.sw is a 16-bit (machine endian) audio file sampled at 32000 Hz to
+96000 Hz. The output file is already decompressed.
+
+For example, for a 44.1 kHz mono stream at ~64kbit/sec and with 256 sample
+frames:
+
+% testcelt 44100 1 256 46 intput.sw output.sw
+
+Since 44100/256*46*8 = 63393.74 bits/sec.
-Alternatively, there are now Ogg-based tools in tools/. Use
-the --help option for details. These are quite similar to the
-speexenc/speexdec tools.
+All even frame sizes from 64 to 512 are currently supported, although
+power-of-two sizes are recommended and most CELT development is done
+using a size of 256. The delay imposed by CELT is 1.25x - 1.5x the
+frame duration depending on the frame size and some details of CELT's
+internal operation. For 256 sample frames the delay is 1.5x or 384
+samples, so the total codec delay in the above example is 8.70ms
+(1000/(44100/384)).
diff --git a/libcelt/bands.h b/libcelt/bands.h
index 8955a49cc3da86c9be34899389d437681c9c0bd5..c1609f222a3dbf7938b9a75450e989c5c7dc6c5e 100644
--- a/libcelt/bands.h
+++ b/libcelt/bands.h
@@ -38,11 +38,6 @@
#include "entdec.h"
#include "rate.h"
-/** Applies a series of rotations so that pulses are spread like a two-sided
-exponential. The effect of this is to reduce the tonal noise created by the
-sparse spectrum resulting from the pulse codebook */
-void exp_rotation(celt_norm_t *X, int len, int dir, int stride, int iter);
-
/** Compute the amplitude (sqrt energy) in each of the bands
* @param m Mode data
* @param X Spectrum
diff --git a/libcelt/celt.c b/libcelt/celt.c
index 9877fe309af08c31d44a2e1fee8297056f03a19c..2774edd69c2054acf2ac386a86ca4b495432e1e9 100644
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -656,10 +656,11 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig_t * pcm, celt_si
}
}
}
- /*fprintf (stderr, "remaining bits after encode = %d\n", nbCompressedBytes*8-ec_enc_tell(&st->enc, 0));*/
- /*if (ec_enc_tell(&st->enc, 0) < nbCompressedBytes*8 - 7)
- celt_warning_int ("many unused bits: ", nbCompressedBytes*8-ec_enc_tell(&st->enc, 0));*/
- /*printf ("%d\n", ec_enc_tell(&st->enc, 0)-8*nbCompressedBytes);*/
+
+ /*fprintf (stderr, "remaining bits after encode = %d\n", nbCompressedBytes*8-ec_enc_tell(&enc, 0));*/
+ /*if (ec_enc_tell(&enc, 0) < nbCompressedBytes*8 - 7)
+ celt_warning_int ("many unused bits: ", nbCompressedBytes*8-ec_enc_tell(&enc, 0));*/
+
/* Finishing the stream with a 0101... pattern so that the decoder can check is everything's right */
{
int val = 0;
diff --git a/libcelt/celt.h b/libcelt/celt.h
index c5bf4eacf575d5d981433fbf895fbc86071b50f2..251007bea6f8810c7ca7141d6eb1652f62585b83 100644
--- a/libcelt/celt.h
+++ b/libcelt/celt.h
@@ -159,7 +159,7 @@ EXPORT void celt_encoder_destroy(CELTEncoder *st);
* (can change from one frame to another)
@return Number of bytes written to "compressed". Should be the same as
* "nbCompressedBytes" unless the stream is VBR. If negative, an error
- * has occured (see error codes). It is IMPORTANT that the length returned
+ * has occurred (see error codes). It is IMPORTANT that the length returned
* be somehow transmitted to the decoder. Otherwise, no decoding is possible.
*/
EXPORT int celt_encode_float(CELTEncoder *st, const float *pcm, float *optional_synthesis, unsigned char *compressed, int nbCompressedBytes);
@@ -176,7 +176,7 @@ EXPORT int celt_encode_float(CELTEncoder *st, const float *pcm, float *optional_
* (can change from one frame to another)
@return Number of bytes written to "compressed". Should be the same as
* "nbCompressedBytes" unless the stream is VBR. If negative, an error
- * has occured (see error codes). It is IMPORTANT that the length returned
+ * has occurred (see error codes). It is IMPORTANT that the length returned
* be somehow transmitted to the decoder. Otherwise, no decoding is possible.
*/
EXPORT int celt_encode(CELTEncoder *st, const celt_int16_t *pcm, celt_int16_t *optional_synthesis, unsigned char *compressed, int nbCompressedBytes);
diff --git a/libcelt/modes.c b/libcelt/modes.c
index 061a7dfa46d9334bddc22626580db57f23dd1b0d..8cced7c30687dd252892eb85f2c400a14dba73fc 100644
--- a/libcelt/modes.c
+++ b/libcelt/modes.c
@@ -1,4 +1,4 @@
-/* (C) 2007-2008 Jean-Marc Valin, CSIRO
+/* (C) 2007-2009 Jean-Marc Valin, CSIRO
(C) 2008 Gregory Maxwell */
/*
Redistribution and use in source and binary forms, with or without
diff --git a/libcelt/quant_bands.c b/libcelt/quant_bands.c
index 3ad16eb24a1d2827b9d41dba4fb29b25b249ecd9..0dd2a7defd9aded109ca6384e02caf7b1d8d1286 100644
--- a/libcelt/quant_bands.c
+++ b/libcelt/quant_bands.c
@@ -112,7 +112,7 @@ static void quant_coarse_energy_mono(const CELTMode *m, celt_ener_t *eBands, cel
celt_word16_t prev = 0;
celt_word16_t coef = m->ePredCoef;
celt_word16_t beta;
- /* The .7 is a heuristic */
+ /* The .8 is a heuristic */
beta = MULT16_16_Q15(QCONST16(.8f,15),coef);
bits = ec_enc_tell(enc, 0);
@@ -196,7 +196,7 @@ static void unquant_coarse_energy_mono(const CELTMode *m, celt_ener_t *eBands, c
unsigned bits;
celt_word16_t prev = 0;
celt_word16_t coef = m->ePredCoef;
- /* The .7 is a heuristic */
+ /* The .8 is a heuristic */
celt_word16_t beta = MULT16_16_Q15(QCONST16(.8f,15),coef);
bits = ec_dec_tell(dec, 0);
diff --git a/libcelt/rate.c b/libcelt/rate.c
index 38b193d10b51b62621b2f10734e4d6d176b0dfb8..8e1a9c00c477096da0fee2f17c8547b002ceb52d 100644
--- a/libcelt/rate.c
+++ b/libcelt/rate.c
@@ -1,4 +1,4 @@
-/* (C) 2007-2008 Jean-Marc Valin, CSIRO
+/* (C) 2007-2009 Jean-Marc Valin, CSIRO
*/
/*
Redistribution and use in source and binary forms, with or without