mirror of https://git.ffmpeg.org/ffmpeg.git
first pass at ALAC decoder from David Hammerton; while David's original
decoder works great, this decoder is not completely and seamlessly integrated yet with FFmpeg Originally committed as revision 4008 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Mike Melanson
parent
2a515c08f2
commit
6d6d7970e7
1
CREDITS
1
CREDITS
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@ -14,6 +14,7 @@ Brian Foley
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Arpad Gereoffy
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Philip Gladstone
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Vladimir Gneushev
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David Hammerton
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Wolfgang Hesseler
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Falk Hueffner
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Zdenek Kabelac
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@ -1,6 +1,6 @@
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#
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# libavcodec Makefile
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# (c) 2000-2003 Fabrice Bellard
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# (c) 2000-2005 Fabrice Bellard
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#
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include ../config.mak
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@ -22,7 +22,8 @@ OBJS= bitstream.o utils.o mem.o allcodecs.o \
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smc.o parser.o flicvideo.o truemotion1.o vmdav.o lcl.o qtrle.o g726.o \
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flac.o vp3dsp.o integer.o snow.o tscc.o sonic.o ulti.o h264idct.o \
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qdrw.o xl.o rangecoder.o png.o pnm.o qpeg.o vc9.o h263.o h261.o \
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msmpeg4.o h263dec.o svq1.o rv10.o wmadec.o indeo3.o shorten.o loco.o
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msmpeg4.o h263dec.o svq1.o rv10.o wmadec.o indeo3.o shorten.o loco.o \
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alac.o
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AMROBJS=
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ifeq ($(AMR_NB),yes)
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@ -0,0 +1,970 @@
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/*
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* ALAC (Apple Lossless Audio Codec) decoder
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* Copyright (c) 2005 David Hammerton
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* All rights reserved.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/**
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* @file alac.c
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* ALAC (Apple Lossless Audio Codec) decoder
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* @author 2005 David Hammerton
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*
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* For more information on the ALAC format, visit:
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* http://crazney.net/programs/itunes/alac.html
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*
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* Note: This decoder expects a 36- (0x24-)byte QuickTime atom to be
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* passed through the extradata[_size] fields. This atom is tacked onto
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* the end of an 'alac' stsd atom and has the following format:
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* bytes 0-3 atom size (0x24), big-endian
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* bytes 4-7 atom type ('alac', not the 'alac' tag from start of stsd)
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* bytes 8-35 data bytes needed by decoder
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*/
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#include "avcodec.h"
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#define ALAC_EXTRADATA_SIZE 36
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struct alac_file {
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unsigned char *input_buffer;
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int input_buffer_index;
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int input_buffer_size;
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int input_buffer_bitaccumulator; /* used so we can do arbitary
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bit reads */
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int samplesize;
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int numchannels;
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int bytespersample;
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/* buffers */
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int32_t *predicterror_buffer_a;
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int32_t *predicterror_buffer_b;
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int32_t *outputsamples_buffer_a;
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int32_t *outputsamples_buffer_b;
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/* stuff from setinfo */
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uint32_t setinfo_max_samples_per_frame; /* 0x1000 = 4096 */ /* max samples per frame? */
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uint8_t setinfo_7a; /* 0x00 */
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uint8_t setinfo_sample_size; /* 0x10 */
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uint8_t setinfo_rice_historymult; /* 0x28 */
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uint8_t setinfo_rice_initialhistory; /* 0x0a */
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uint8_t setinfo_rice_kmodifier; /* 0x0e */
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uint8_t setinfo_7f; /* 0x02 */
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uint16_t setinfo_80; /* 0x00ff */
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uint32_t setinfo_82; /* 0x000020e7 */
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uint32_t setinfo_86; /* 0x00069fe4 */
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uint32_t setinfo_8a_rate; /* 0x0000ac44 */
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/* end setinfo stuff */
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};
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typedef struct alac_file alac_file;
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typedef struct {
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AVCodecContext *avctx;
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/* init to 0; first frame decode should initialize from extradata and
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* set this to 1 */
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int context_initialized;
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alac_file *alac;
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} ALACContext;
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static void allocate_buffers(alac_file *alac)
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{
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alac->predicterror_buffer_a = av_malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->predicterror_buffer_b = av_malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->outputsamples_buffer_a = av_malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->outputsamples_buffer_b = av_malloc(alac->setinfo_max_samples_per_frame * 4);
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}
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void alac_set_info(alac_file *alac, char *inputbuffer)
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{
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char *ptr = inputbuffer;
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ptr += 4; /* size */
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ptr += 4; /* alac */
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ptr += 4; /* 0 ? */
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alac->setinfo_max_samples_per_frame = BE_32(ptr); /* buffer size / 2 ? */
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ptr += 4;
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alac->setinfo_7a = *ptr++;
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alac->setinfo_sample_size = *ptr++;
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alac->setinfo_rice_historymult = *ptr++;
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alac->setinfo_rice_initialhistory = *ptr++;
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alac->setinfo_rice_kmodifier = *ptr++;
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alac->setinfo_7f = *ptr++;
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alac->setinfo_80 = BE_16(ptr);
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ptr += 2;
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alac->setinfo_82 = BE_32(ptr);
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ptr += 4;
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alac->setinfo_86 = BE_32(ptr);
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ptr += 4;
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alac->setinfo_8a_rate = BE_32(ptr);
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ptr += 4;
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allocate_buffers(alac);
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}
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/* stream reading */
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/* supports reading 1 to 16 bits, in big endian format */
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static uint32_t readbits_16(alac_file *alac, int bits)
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{
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uint32_t result;
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int new_accumulator;
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if (alac->input_buffer_index + 2 >= alac->input_buffer_size) {
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av_log(NULL, AV_LOG_INFO, "alac: input buffer went out of bounds (%d >= %d)\n",
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alac->input_buffer_index + 2, alac->input_buffer_size);
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exit (0);
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}
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result = (alac->input_buffer[alac->input_buffer_index + 0] << 16) |
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(alac->input_buffer[alac->input_buffer_index + 1] << 8) |
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(alac->input_buffer[alac->input_buffer_index + 2]);
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/* shift left by the number of bits we've already read,
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* so that the top 'n' bits of the 24 bits we read will
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* be the return bits */
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result = result << alac->input_buffer_bitaccumulator;
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result = result & 0x00ffffff;
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/* and then only want the top 'n' bits from that, where
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* n is 'bits' */
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result = result >> (24 - bits);
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new_accumulator = (alac->input_buffer_bitaccumulator + bits);
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/* increase the buffer pointer if we've read over n bytes. */
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alac->input_buffer_index += (new_accumulator >> 3);
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/* and the remainder goes back into the bit accumulator */
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alac->input_buffer_bitaccumulator = (new_accumulator & 7);
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return result;
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}
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/* supports reading 1 to 32 bits, in big endian format */
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static uint32_t readbits(alac_file *alac, int bits)
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{
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int32_t result = 0;
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if (bits > 16) {
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bits -= 16;
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result = readbits_16(alac, 16) << bits;
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}
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result |= readbits_16(alac, bits);
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return result;
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}
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/* reads a single bit */
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static int readbit(alac_file *alac)
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{
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int result;
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int new_accumulator;
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if (alac->input_buffer_index >= alac->input_buffer_size) {
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av_log(NULL, AV_LOG_INFO, "alac: input buffer went out of bounds (%d >= %d)\n",
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alac->input_buffer_index + 2, alac->input_buffer_size);
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exit (0);
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}
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result = alac->input_buffer[alac->input_buffer_index];
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result = result << alac->input_buffer_bitaccumulator;
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result = result >> 7 & 1;
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new_accumulator = (alac->input_buffer_bitaccumulator + 1);
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alac->input_buffer_index += (new_accumulator / 8);
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alac->input_buffer_bitaccumulator = (new_accumulator % 8);
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return result;
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}
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static void unreadbits(alac_file *alac, int bits)
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{
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int new_accumulator = (alac->input_buffer_bitaccumulator - bits);
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alac->input_buffer_index += (new_accumulator >> 3);
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alac->input_buffer_bitaccumulator = (new_accumulator & 7);
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if (alac->input_buffer_bitaccumulator < 0)
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alac->input_buffer_bitaccumulator *= -1;
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}
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/* hideously inefficient. could use a bitmask search,
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* alternatively bsr on x86,
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*/
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static int count_leading_zeros(int32_t input)
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{
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int i = 0;
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while (!(0x80000000 & input) && i < 32) {
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i++;
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input = input << 1;
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}
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return i;
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}
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void bastardized_rice_decompress(alac_file *alac,
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int32_t *output_buffer,
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int output_size,
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int readsamplesize, /* arg_10 */
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int rice_initialhistory, /* arg424->b */
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int rice_kmodifier, /* arg424->d */
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int rice_historymult, /* arg424->c */
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int rice_kmodifier_mask /* arg424->e */
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)
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{
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int output_count;
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unsigned int history = rice_initialhistory;
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int sign_modifier = 0;
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for (output_count = 0; output_count < output_size; output_count++) {
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int32_t x = 0;
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int32_t x_modified;
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int32_t final_val;
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/* read x - number of 1s before 0 represent the rice */
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while (x <= 8 && readbit(alac)) {
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x++;
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}
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if (x > 8) { /* RICE THRESHOLD */
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/* use alternative encoding */
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int32_t value;
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value = readbits(alac, readsamplesize);
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/* mask value to readsamplesize size */
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if (readsamplesize != 32)
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value &= (0xffffffff >> (32 - readsamplesize));
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x = value;
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} else {
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/* standard rice encoding */
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int extrabits;
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int k; /* size of extra bits */
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/* read k, that is bits as is */
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k = 31 - rice_kmodifier - count_leading_zeros((history >> 9) + 3);
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if (k < 0)
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k += rice_kmodifier;
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else
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k = rice_kmodifier;
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if (k != 1) {
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extrabits = readbits(alac, k);
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/* multiply x by 2^k - 1, as part of their strange algorithm */
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x = (x << k) - x;
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if (extrabits > 1) {
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x += extrabits - 1;
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} else
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unreadbits(alac, 1);
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}
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}
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x_modified = sign_modifier + x;
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final_val = (x_modified + 1) / 2;
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if (x_modified & 1) final_val *= -1;
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output_buffer[output_count] = final_val;
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sign_modifier = 0;
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/* now update the history */
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history += (x_modified * rice_historymult)
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- ((history * rice_historymult) >> 9);
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if (x_modified > 0xffff)
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history = 0xffff;
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/* special case: there may be compressed blocks of 0 */
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if ((history < 128) && (output_count+1 < output_size)) {
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int block_size;
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sign_modifier = 1;
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x = 0;
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while (x <= 8 && readbit(alac)) {
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x++;
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}
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if (x > 8) {
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block_size = readbits(alac, 16);
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block_size &= 0xffff;
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} else {
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int k;
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int extrabits;
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k = count_leading_zeros(history) + ((history + 16) >> 6 /* / 64 */) - 24;
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extrabits = readbits(alac, k);
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block_size = (((1 << k) - 1) & rice_kmodifier_mask) * x
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+ extrabits - 1;
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if (extrabits < 2) {
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x = 1 - extrabits;
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block_size += x;
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unreadbits(alac, 1);
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}
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}
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if (block_size > 0) {
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memset(&output_buffer[output_count+1], 0, block_size * 4);
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output_count += block_size;
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}
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if (block_size > 0xffff)
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sign_modifier = 0;
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history = 0;
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}
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}
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}
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#define SIGN_EXTENDED32(val, bits) ((val << (32 - bits)) >> (32 - bits))
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#define SIGN_ONLY(v) \
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((v < 0) ? (-1) : \
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((v > 0) ? (1) : \
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(0)))
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static void predictor_decompress_fir_adapt(int32_t *error_buffer,
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int32_t *buffer_out,
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int output_size,
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int readsamplesize,
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int16_t *predictor_coef_table,
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int predictor_coef_num,
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int predictor_quantitization)
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{
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int i;
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/* first sample always copies */
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*buffer_out = *error_buffer;
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|
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if (!predictor_coef_num) {
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if (output_size <= 1) return;
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memcpy(buffer_out+1, error_buffer+1, (output_size-1) * 4);
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return;
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}
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|
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if (predictor_coef_num == 0x1f) { /* 11111 - max value of predictor_coef_num */
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/* second-best case scenario for fir decompression,
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* error describes a small difference from the previous sample only
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*/
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if (output_size <= 1) return;
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for (i = 0; i < output_size - 1; i++) {
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int32_t prev_value;
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int32_t error_value;
|
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prev_value = buffer_out[i];
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error_value = error_buffer[i+1];
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buffer_out[i+1] = SIGN_EXTENDED32((prev_value + error_value), readsamplesize);
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}
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return;
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}
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|
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/* read warm-up samples */
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if (predictor_coef_num > 0) {
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int i;
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for (i = 0; i < predictor_coef_num; i++) {
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int32_t val;
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val = buffer_out[i] + error_buffer[i+1];
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val = SIGN_EXTENDED32(val, readsamplesize);
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buffer_out[i+1] = val;
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}
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}
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#if 0
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/* 4 and 8 are very common cases (the only ones i've seen). these
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* should be unrolled and optimised
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*/
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if (predictor_coef_num == 4) {
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/* FIXME: optimised general case */
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return;
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}
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if (predictor_coef_table == 8) {
|
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/* FIXME: optimised general case */
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return;
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}
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#endif
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/* general case */
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if (predictor_coef_num > 0) {
|
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for (i = predictor_coef_num + 1;
|
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i < output_size;
|
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i++) {
|
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int j;
|
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int sum = 0;
|
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int outval;
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int error_val = error_buffer[i];
|
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for (j = 0; j < predictor_coef_num; j++) {
|
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sum += (buffer_out[predictor_coef_num-j] - buffer_out[0]) *
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predictor_coef_table[j];
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}
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outval = (1 << (predictor_quantitization-1)) + sum;
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outval = outval >> predictor_quantitization;
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outval = outval + buffer_out[0] + error_val;
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outval = SIGN_EXTENDED32(outval, readsamplesize);
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buffer_out[predictor_coef_num+1] = outval;
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|
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if (error_val > 0) {
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int predictor_num = predictor_coef_num - 1;
|
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|
||||
while (predictor_num >= 0 && error_val > 0) {
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int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
|
||||
int sign = SIGN_ONLY(val);
|
||||
|
||||
predictor_coef_table[predictor_num] -= sign;
|
||||
|
||||
val *= sign; /* absolute value */
|
||||
|
||||
error_val -= ((val >> predictor_quantitization) *
|
||||
(predictor_coef_num - predictor_num));
|
||||
|
||||
predictor_num--;
|
||||
}
|
||||
} else if (error_val < 0) {
|
||||
int predictor_num = predictor_coef_num - 1;
|
||||
|
||||
while (predictor_num >= 0 && error_val < 0) {
|
||||
int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
|
||||
int sign = - SIGN_ONLY(val);
|
||||
|
||||
predictor_coef_table[predictor_num] -= sign;
|
||||
|
||||
val *= sign; /* neg value */
|
||||
|
||||
error_val -= ((val >> predictor_quantitization) *
|
||||
(predictor_coef_num - predictor_num));
|
||||
|
||||
predictor_num--;
|
||||
}
|
||||
}
|
||||
|
||||
buffer_out++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void deinterlace_16(int32_t *buffer_a, int32_t *buffer_b,
|
||||
int16_t *buffer_out,
|
||||
int numchannels, int numsamples,
|
||||
uint8_t interlacing_shift,
|
||||
uint8_t interlacing_leftweight) {
|
||||
|
||||
int i;
|
||||
if (numsamples <= 0) return;
|
||||
|
||||
/* weighted interlacing */
|
||||
if (interlacing_leftweight) {
|
||||
for (i = 0; i < numsamples; i++) {
|
||||
int32_t difference, midright;
|
||||
int16_t left;
|
||||
int16_t right;
|
||||
|
||||
midright = buffer_a[i];
|
||||
difference = buffer_b[i];
|
||||
|
||||
|
||||
right = midright - ((difference * interlacing_leftweight) >> interlacing_shift);
|
||||
left = (midright - ((difference * interlacing_leftweight) >> interlacing_shift))
|
||||
+ difference;
|
||||
|
||||
/* output is always little endian */
|
||||
/*
|
||||
if (host_bigendian) {
|
||||
be2me_16(left);
|
||||
be2me_16(right);
|
||||
}
|
||||
*/
|
||||
|
||||
buffer_out[i*numchannels] = left;
|
||||
buffer_out[i*numchannels + 1] = right;
|
||||
}
|
||||
|
||||
return;
|
||||
}
|
||||
|
||||
/* otherwise basic interlacing took place */
|
||||
for (i = 0; i < numsamples; i++) {
|
||||
int16_t left, right;
|
||||
|
||||
left = buffer_a[i];
|
||||
right = buffer_b[i];
|
||||
|
||||
/* output is always little endian */
|
||||
/*
|
||||
if (host_bigendian) {
|
||||
be2me_16(left);
|
||||
be2me_16(right);
|
||||
}
|
||||
*/
|
||||
|
||||
buffer_out[i*numchannels] = left;
|
||||
buffer_out[i*numchannels + 1] = right;
|
||||
}
|
||||
}
|
||||
|
||||
int decode_frame(ALACContext *s, alac_file *alac,
|
||||
unsigned char *inbuffer,
|
||||
int input_buffer_size,
|
||||
void *outbuffer, int *outputsize){
|
||||
|
||||
int channels;
|
||||
int32_t outputsamples = alac->setinfo_max_samples_per_frame;
|
||||
|
||||
/* initialize from the extradata */
|
||||
if (!s->context_initialized) {
|
||||
if (s->avctx->extradata_size != ALAC_EXTRADATA_SIZE) {
|
||||
av_log(NULL, AV_LOG_ERROR, "alac: expected %d extradata bytes\n",
|
||||
ALAC_EXTRADATA_SIZE);
|
||||
return input_buffer_size;
|
||||
}
|
||||
alac_set_info(s->alac, s->avctx->extradata);
|
||||
s->context_initialized = 1;
|
||||
}
|
||||
|
||||
|
||||
/* setup the stream */
|
||||
alac->input_buffer = inbuffer;
|
||||
alac->input_buffer_index = 0;
|
||||
alac->input_buffer_size = input_buffer_size;
|
||||
alac->input_buffer_bitaccumulator = 0;
|
||||
|
||||
channels = readbits(alac, 3);
|
||||
|
||||
*outputsize = outputsamples * alac->bytespersample;
|
||||
|
||||
switch(channels) {
|
||||
case 0: { /* 1 channel */
|
||||
int hassize;
|
||||
int isnotcompressed;
|
||||
int readsamplesize;
|
||||
|
||||
int wasted_bytes;
|
||||
int ricemodifier;
|
||||
|
||||
|
||||
/* 2^result = something to do with output waiting.
|
||||
* perhaps matters if we read > 1 frame in a pass?
|
||||
*/
|
||||
readbits(alac, 4);
|
||||
|
||||
readbits(alac, 12); /* unknown, skip 12 bits */
|
||||
|
||||
hassize = readbits(alac, 1); /* the output sample size is stored soon */
|
||||
|
||||
wasted_bytes = readbits(alac, 2); /* unknown ? */
|
||||
|
||||
isnotcompressed = readbits(alac, 1); /* whether the frame is compressed */
|
||||
|
||||
if (hassize) {
|
||||
/* now read the number of samples,
|
||||
* as a 32bit integer */
|
||||
outputsamples = readbits(alac, 32);
|
||||
*outputsize = outputsamples * alac->bytespersample;
|
||||
}
|
||||
|
||||
readsamplesize = alac->setinfo_sample_size - (wasted_bytes * 8);
|
||||
|
||||
if (!isnotcompressed) {
|
||||
/* so it is compressed */
|
||||
int16_t predictor_coef_table[32];
|
||||
int predictor_coef_num;
|
||||
int prediction_type;
|
||||
int prediction_quantitization;
|
||||
int i;
|
||||
|
||||
/* skip 16 bits, not sure what they are. seem to be used in
|
||||
* two channel case */
|
||||
readbits(alac, 8);
|
||||
readbits(alac, 8);
|
||||
|
||||
prediction_type = readbits(alac, 4);
|
||||
prediction_quantitization = readbits(alac, 4);
|
||||
|
||||
ricemodifier = readbits(alac, 3);
|
||||
predictor_coef_num = readbits(alac, 5);
|
||||
|
||||
/* read the predictor table */
|
||||
for (i = 0; i < predictor_coef_num; i++) {
|
||||
predictor_coef_table[i] = (int16_t)readbits(alac, 16);
|
||||
}
|
||||
|
||||
if (wasted_bytes) {
|
||||
/* these bytes seem to have something to do with
|
||||
* > 2 channel files.
|
||||
*/
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unimplemented, unhandling of wasted_bytes\n");
|
||||
}
|
||||
|
||||
bastardized_rice_decompress(alac,
|
||||
alac->predicterror_buffer_a,
|
||||
outputsamples,
|
||||
readsamplesize,
|
||||
alac->setinfo_rice_initialhistory,
|
||||
alac->setinfo_rice_kmodifier,
|
||||
ricemodifier * alac->setinfo_rice_historymult / 4,
|
||||
(1 << alac->setinfo_rice_kmodifier) - 1);
|
||||
|
||||
if (prediction_type == 0) {
|
||||
/* adaptive fir */
|
||||
predictor_decompress_fir_adapt(alac->predicterror_buffer_a,
|
||||
alac->outputsamples_buffer_a,
|
||||
outputsamples,
|
||||
readsamplesize,
|
||||
predictor_coef_table,
|
||||
predictor_coef_num,
|
||||
prediction_quantitization);
|
||||
} else {
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type);
|
||||
/* i think the only other prediction type (or perhaps this is just a
|
||||
* boolean?) runs adaptive fir twice.. like:
|
||||
* predictor_decompress_fir_adapt(predictor_error, tempout, ...)
|
||||
* predictor_decompress_fir_adapt(predictor_error, outputsamples ...)
|
||||
* little strange..
|
||||
*/
|
||||
}
|
||||
|
||||
} else {
|
||||
/* not compressed, easy case */
|
||||
if (readsamplesize <= 16) {
|
||||
int i;
|
||||
for (i = 0; i < outputsamples; i++) {
|
||||
int32_t audiobits = readbits(alac, readsamplesize);
|
||||
|
||||
audiobits = SIGN_EXTENDED32(audiobits, readsamplesize);
|
||||
|
||||
alac->outputsamples_buffer_a[i] = audiobits;
|
||||
}
|
||||
} else {
|
||||
int i;
|
||||
for (i = 0; i < outputsamples; i++) {
|
||||
int32_t audiobits;
|
||||
|
||||
audiobits = readbits(alac, 16);
|
||||
/* special case of sign extension..
|
||||
* as we'll be ORing the low 16bits into this */
|
||||
audiobits = audiobits << 16;
|
||||
audiobits = audiobits >> (32 - readsamplesize);
|
||||
|
||||
audiobits |= readbits(alac, readsamplesize - 16);
|
||||
|
||||
alac->outputsamples_buffer_a[i] = audiobits;
|
||||
}
|
||||
}
|
||||
/* wasted_bytes = 0; // unused */
|
||||
}
|
||||
|
||||
switch(alac->setinfo_sample_size) {
|
||||
case 16: {
|
||||
int i;
|
||||
for (i = 0; i < outputsamples; i++) {
|
||||
int16_t sample = alac->outputsamples_buffer_a[i];
|
||||
be2me_16(sample);
|
||||
((int16_t*)outbuffer)[i * alac->numchannels] = sample;
|
||||
}
|
||||
break;
|
||||
}
|
||||
case 20:
|
||||
case 24:
|
||||
case 32:
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unimplemented sample size %i\n", alac->setinfo_sample_size);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
}
|
||||
case 1: { /* 2 channels */
|
||||
int hassize;
|
||||
int isnotcompressed;
|
||||
int readsamplesize;
|
||||
|
||||
int wasted_bytes;
|
||||
|
||||
uint8_t interlacing_shift;
|
||||
uint8_t interlacing_leftweight;
|
||||
|
||||
/* 2^result = something to do with output waiting.
|
||||
* perhaps matters if we read > 1 frame in a pass?
|
||||
*/
|
||||
readbits(alac, 4);
|
||||
|
||||
readbits(alac, 12); /* unknown, skip 12 bits */
|
||||
|
||||
hassize = readbits(alac, 1); /* the output sample size is stored soon */
|
||||
|
||||
wasted_bytes = readbits(alac, 2); /* unknown ? */
|
||||
|
||||
isnotcompressed = readbits(alac, 1); /* whether the frame is compressed */
|
||||
|
||||
if (hassize) {
|
||||
/* now read the number of samples,
|
||||
* as a 32bit integer */
|
||||
outputsamples = readbits(alac, 32);
|
||||
*outputsize = outputsamples * alac->bytespersample;
|
||||
}
|
||||
|
||||
readsamplesize = alac->setinfo_sample_size - (wasted_bytes * 8) + 1;
|
||||
|
||||
if (!isnotcompressed) {
|
||||
/* compressed */
|
||||
int16_t predictor_coef_table_a[32];
|
||||
int predictor_coef_num_a;
|
||||
int prediction_type_a;
|
||||
int prediction_quantitization_a;
|
||||
int ricemodifier_a;
|
||||
|
||||
int16_t predictor_coef_table_b[32];
|
||||
int predictor_coef_num_b;
|
||||
int prediction_type_b;
|
||||
int prediction_quantitization_b;
|
||||
int ricemodifier_b;
|
||||
|
||||
int i;
|
||||
|
||||
interlacing_shift = readbits(alac, 8);
|
||||
interlacing_leftweight = readbits(alac, 8);
|
||||
|
||||
/******** channel 1 ***********/
|
||||
prediction_type_a = readbits(alac, 4);
|
||||
prediction_quantitization_a = readbits(alac, 4);
|
||||
|
||||
ricemodifier_a = readbits(alac, 3);
|
||||
predictor_coef_num_a = readbits(alac, 5);
|
||||
|
||||
/* read the predictor table */
|
||||
for (i = 0; i < predictor_coef_num_a; i++) {
|
||||
predictor_coef_table_a[i] = (int16_t)readbits(alac, 16);
|
||||
}
|
||||
|
||||
/******** channel 2 *********/
|
||||
prediction_type_b = readbits(alac, 4);
|
||||
prediction_quantitization_b = readbits(alac, 4);
|
||||
|
||||
ricemodifier_b = readbits(alac, 3);
|
||||
predictor_coef_num_b = readbits(alac, 5);
|
||||
|
||||
/* read the predictor table */
|
||||
for (i = 0; i < predictor_coef_num_b; i++) {
|
||||
predictor_coef_table_b[i] = (int16_t)readbits(alac, 16);
|
||||
}
|
||||
|
||||
/*********************/
|
||||
if (wasted_bytes) {
|
||||
/* see mono case */
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unimplemented, unhandling of wasted_bytes\n");
|
||||
}
|
||||
|
||||
/* channel 1 */
|
||||
bastardized_rice_decompress(alac,
|
||||
alac->predicterror_buffer_a,
|
||||
outputsamples,
|
||||
readsamplesize,
|
||||
alac->setinfo_rice_initialhistory,
|
||||
alac->setinfo_rice_kmodifier,
|
||||
ricemodifier_a * alac->setinfo_rice_historymult / 4,
|
||||
(1 << alac->setinfo_rice_kmodifier) - 1);
|
||||
|
||||
if (prediction_type_a == 0) {
|
||||
/* adaptive fir */
|
||||
predictor_decompress_fir_adapt(alac->predicterror_buffer_a,
|
||||
alac->outputsamples_buffer_a,
|
||||
outputsamples,
|
||||
readsamplesize,
|
||||
predictor_coef_table_a,
|
||||
predictor_coef_num_a,
|
||||
prediction_quantitization_a);
|
||||
} else {
|
||||
/* see mono case */
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type_a);
|
||||
}
|
||||
|
||||
/* channel 2 */
|
||||
bastardized_rice_decompress(alac,
|
||||
alac->predicterror_buffer_b,
|
||||
outputsamples,
|
||||
readsamplesize,
|
||||
alac->setinfo_rice_initialhistory,
|
||||
alac->setinfo_rice_kmodifier,
|
||||
ricemodifier_b * alac->setinfo_rice_historymult / 4,
|
||||
(1 << alac->setinfo_rice_kmodifier) - 1);
|
||||
|
||||
if (prediction_type_b == 0) {
|
||||
/* adaptive fir */
|
||||
predictor_decompress_fir_adapt(alac->predicterror_buffer_b,
|
||||
alac->outputsamples_buffer_b,
|
||||
outputsamples,
|
||||
readsamplesize,
|
||||
predictor_coef_table_b,
|
||||
predictor_coef_num_b,
|
||||
prediction_quantitization_b);
|
||||
} else {
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type_b);
|
||||
}
|
||||
} else {
|
||||
/* not compressed, easy case */
|
||||
if (alac->setinfo_sample_size <= 16) {
|
||||
int i;
|
||||
for (i = 0; i < outputsamples; i++) {
|
||||
int32_t audiobits_a, audiobits_b;
|
||||
|
||||
audiobits_a = readbits(alac, alac->setinfo_sample_size);
|
||||
audiobits_b = readbits(alac, alac->setinfo_sample_size);
|
||||
|
||||
audiobits_a = SIGN_EXTENDED32(audiobits_a, alac->setinfo_sample_size);
|
||||
audiobits_b = SIGN_EXTENDED32(audiobits_b, alac->setinfo_sample_size);
|
||||
|
||||
alac->outputsamples_buffer_a[i] = audiobits_a;
|
||||
alac->outputsamples_buffer_b[i] = audiobits_b;
|
||||
}
|
||||
} else {
|
||||
int i;
|
||||
for (i = 0; i < outputsamples; i++) {
|
||||
int32_t audiobits_a, audiobits_b;
|
||||
|
||||
audiobits_a = readbits(alac, 16);
|
||||
audiobits_a = audiobits_a << 16;
|
||||
audiobits_a = audiobits_a >> (32 - alac->setinfo_sample_size);
|
||||
audiobits_a |= readbits(alac, alac->setinfo_sample_size - 16);
|
||||
|
||||
audiobits_b = readbits(alac, 16);
|
||||
audiobits_b = audiobits_b << 16;
|
||||
audiobits_b = audiobits_b >> (32 - alac->setinfo_sample_size);
|
||||
audiobits_b |= readbits(alac, alac->setinfo_sample_size - 16);
|
||||
|
||||
alac->outputsamples_buffer_a[i] = audiobits_a;
|
||||
alac->outputsamples_buffer_b[i] = audiobits_b;
|
||||
}
|
||||
}
|
||||
/* wasted_bytes = 0; */
|
||||
interlacing_shift = 0;
|
||||
interlacing_leftweight = 0;
|
||||
}
|
||||
|
||||
switch(alac->setinfo_sample_size) {
|
||||
case 16: {
|
||||
deinterlace_16(alac->outputsamples_buffer_a,
|
||||
alac->outputsamples_buffer_b,
|
||||
(int16_t*)outbuffer,
|
||||
alac->numchannels,
|
||||
outputsamples,
|
||||
interlacing_shift,
|
||||
interlacing_leftweight);
|
||||
break;
|
||||
}
|
||||
case 20:
|
||||
case 24:
|
||||
case 32:
|
||||
av_log(NULL, AV_LOG_ERROR, "FIXME: unimplemented sample size %i\n", alac->setinfo_sample_size);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
av_log(NULL, AV_LOG_INFO, "buf size = %d, consumed %d\n",
|
||||
input_buffer_size, alac->input_buffer_index);
|
||||
|
||||
/* avoid infinite loop: if decoder consumed 0 bytes; report all bytes
|
||||
* consumed */
|
||||
// if (alac->input_buffer_index)
|
||||
// return alac->input_buffer_index;
|
||||
// else
|
||||
return input_buffer_size;
|
||||
}
|
||||
|
||||
static int alac_decode_init(AVCodecContext * avctx)
|
||||
{
|
||||
ALACContext *s = avctx->priv_data;
|
||||
s->avctx = avctx;
|
||||
s->context_initialized = 0;
|
||||
|
||||
s->alac = av_malloc(sizeof(alac_file));
|
||||
|
||||
s->alac->samplesize = s->avctx->bits_per_sample;
|
||||
s->alac->numchannels = s->avctx->channels;
|
||||
s->alac->bytespersample = (s->alac->samplesize / 8) * s->alac->numchannels;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int alac_decode_frame(AVCodecContext *avctx,
|
||||
void *data, int *data_size,
|
||||
uint8_t *buf, int buf_size)
|
||||
{
|
||||
ALACContext *s = avctx->priv_data;
|
||||
int bytes_consumed = buf_size;
|
||||
|
||||
if (buf)
|
||||
bytes_consumed = decode_frame(s, s->alac, buf, buf_size,
|
||||
data, data_size);
|
||||
|
||||
return bytes_consumed;
|
||||
}
|
||||
|
||||
static int alac_decode_close(AVCodecContext *avctx)
|
||||
{
|
||||
ALACContext *s = avctx->priv_data;
|
||||
|
||||
av_free(s->alac->predicterror_buffer_a);
|
||||
av_free(s->alac->predicterror_buffer_b);
|
||||
|
||||
av_free(s->alac->outputsamples_buffer_a);
|
||||
av_free(s->alac->outputsamples_buffer_b);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
AVCodec alac_decoder = {
|
||||
"alac",
|
||||
CODEC_TYPE_AUDIO,
|
||||
CODEC_ID_ALAC,
|
||||
sizeof(ALACContext),
|
||||
alac_decode_init,
|
||||
NULL,
|
||||
alac_decode_close,
|
||||
alac_decode_frame,
|
||||
};
|
||||
|
|
@ -196,6 +196,7 @@ void avcodec_register_all(void)
|
|||
register_avcodec(&qtrle_decoder);
|
||||
register_avcodec(&flac_decoder);
|
||||
register_avcodec(&shorten_decoder);
|
||||
register_avcodec(&alac_decoder);
|
||||
#endif /* CONFIG_DECODERS */
|
||||
|
||||
#ifdef AMR_NB
|
||||
|
|
|
|||
|
|
@ -17,7 +17,7 @@ extern "C" {
|
|||
|
||||
#define FFMPEG_VERSION_INT 0x000409
|
||||
#define FFMPEG_VERSION "0.4.9-pre1"
|
||||
#define LIBAVCODEC_BUILD 4744
|
||||
#define LIBAVCODEC_BUILD 4745
|
||||
|
||||
#define LIBAVCODEC_VERSION_INT FFMPEG_VERSION_INT
|
||||
#define LIBAVCODEC_VERSION FFMPEG_VERSION
|
||||
|
|
@ -170,6 +170,7 @@ enum CodecID {
|
|||
|
||||
CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG2 transport
|
||||
stream (only used by libavformat) */
|
||||
CODEC_ID_ALAC,
|
||||
};
|
||||
|
||||
/* CODEC_ID_MP3LAME is absolete */
|
||||
|
|
@ -2011,6 +2012,7 @@ extern AVCodec xl_decoder;
|
|||
extern AVCodec qpeg_decoder;
|
||||
extern AVCodec shorten_decoder;
|
||||
extern AVCodec loco_decoder;
|
||||
extern AVCodec alac_decoder;
|
||||
|
||||
/* pcm codecs */
|
||||
#define PCM_CODEC(id, name) \
|
||||
|
|
|
|||
|
|
@ -142,6 +142,7 @@ static const CodecTag mov_audio_tags[] = {
|
|||
{ CODEC_ID_AMR_NB, MKTAG('s', 'a', 'm', 'r') }, /* AMR-NB 3gp */
|
||||
{ CODEC_ID_AMR_WB, MKTAG('s', 'a', 'w', 'b') }, /* AMR-WB 3gp */
|
||||
{ CODEC_ID_AC3, MKTAG('m', 's', 0x20, 0x00) }, /* Dolby AC-3 */
|
||||
{ CODEC_ID_ALAC,MKTAG('a', 'l', 'a', 'c') }, /* Apple Lossless */
|
||||
{ CODEC_ID_NONE, 0 },
|
||||
};
|
||||
|
||||
|
|
@ -1101,6 +1102,23 @@ static int mov_read_stsd(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
|
|||
st->codec.channels = (px[1] >> 3) & 15;
|
||||
}
|
||||
}
|
||||
else if( st->codec.codec_tag == MKTAG( 'a', 'l', 'a', 'c' ))
|
||||
{
|
||||
/* Handle alac audio tag + special extradata */
|
||||
get_be32(pb); /* version */
|
||||
get_be32(pb);
|
||||
st->codec.channels = get_be16(pb); /* channels */
|
||||
st->codec.bits_per_sample = get_be16(pb); /* bits per sample */
|
||||
get_be32(pb);
|
||||
st->codec.sample_rate = get_be16(pb);
|
||||
get_be16(pb);
|
||||
|
||||
/* fetch the 36-byte extradata needed for alac decoding */
|
||||
st->codec.extradata_size = 36;
|
||||
st->codec.extradata = (uint8_t*)
|
||||
av_mallocz(st->codec.extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
|
||||
get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
|
||||
}
|
||||
else if(size>=(16+20))
|
||||
{//16 bytes read, reading atleast 20 more
|
||||
uint16_t version;
|
||||
|
|
|
|||
Loading…
Reference in New Issue