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1 4f52c312 Michael Niedermayer
/*
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 * FLAC (Free Lossless Audio Codec) decoder
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 * Copyright (c) 2003 Alex Beregszaszi
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg 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 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file libavcodec/flacdec.c
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 * FLAC (Free Lossless Audio Codec) decoder
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 * @author Alex Beregszaszi
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 *
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 * For more information on the FLAC format, visit:
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 *  http://flac.sourceforge.net/
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 *
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 * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
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 * through, starting from the initial 'fLaC' signature; or by passing the
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 * 34-byte streaminfo structure through avctx->extradata[_size] followed
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 * by data starting with the 0xFFF8 marker.
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 */
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#include <limits.h>
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#include "libavutil/crc.h"
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#include "avcodec.h"
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#include "internal.h"
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#include "bitstream.h"
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#include "golomb.h"
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#include "flac.h"
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#undef NDEBUG
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#include <assert.h>
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#define MAX_CHANNELS 8
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#define MAX_BLOCKSIZE 65535
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enum decorrelation_type {
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    INDEPENDENT,
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    LEFT_SIDE,
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    RIGHT_SIDE,
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    MID_SIDE,
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};
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typedef struct FLACContext {
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    FLACSTREAMINFO
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    AVCodecContext *avctx;                  ///< parent AVCodecContext
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    GetBitContext gb;                       ///< GetBitContext initialized to start at the current frame
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    int blocksize;                          ///< number of samples in the current frame
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    int curr_bps;                           ///< bps for current subframe, adjusted for channel correlation and wasted bits
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    int sample_shift;                       ///< shift required to make output samples 16-bit or 32-bit
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    int is32;                               ///< flag to indicate if output should be 32-bit instead of 16-bit
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    enum decorrelation_type decorrelation;  ///< channel decorrelation type in the current frame
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    int got_streaminfo;                     ///< indicates if the STREAMINFO has been read
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    int32_t *decoded[MAX_CHANNELS];         ///< decoded samples
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    uint8_t *bitstream;
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    unsigned int bitstream_size;
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    unsigned int bitstream_index;
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    unsigned int allocated_bitstream_size;
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} FLACContext;
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78 cf2baeb3 Stefan Gehrer
static const int sample_rate_table[] =
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{ 0,
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  88200, 176400, 192000,
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  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
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  0, 0, 0, 0 };
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static const int sample_size_table[] =
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{ 0, 8, 12, 0, 16, 20, 24, 0 };
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static const int blocksize_table[] = {
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     0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
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256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
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};
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static int64_t get_utf8(GetBitContext *gb)
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{
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    int64_t val;
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    GET_UTF8(val, get_bits(gb, 8), return -1;)
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    return val;
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}
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static void allocate_buffers(FLACContext *s);
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int ff_flac_is_extradata_valid(AVCodecContext *avctx,
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                               enum FLACExtradataFormat *format,
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                               uint8_t **streaminfo_start)
104
{
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    if (!avctx->extradata || avctx->extradata_size < FLAC_STREAMINFO_SIZE) {
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        av_log(avctx, AV_LOG_ERROR, "extradata NULL or too small.\n");
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        return 0;
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    }
109
    if (AV_RL32(avctx->extradata) != MKTAG('f','L','a','C')) {
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        /* extradata contains STREAMINFO only */
111
        if (avctx->extradata_size != FLAC_STREAMINFO_SIZE) {
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            av_log(avctx, AV_LOG_WARNING, "extradata contains %d bytes too many.\n",
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                   FLAC_STREAMINFO_SIZE-avctx->extradata_size);
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        }
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        *format = FLAC_EXTRADATA_FORMAT_STREAMINFO;
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        *streaminfo_start = avctx->extradata;
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    } else {
118
        if (avctx->extradata_size < 8+FLAC_STREAMINFO_SIZE) {
119
            av_log(avctx, AV_LOG_ERROR, "extradata too small.\n");
120
            return 0;
121
        }
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        *format = FLAC_EXTRADATA_FORMAT_FULL_HEADER;
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        *streaminfo_start = &avctx->extradata[8];
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    }
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    return 1;
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}
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static av_cold int flac_decode_init(AVCodecContext *avctx)
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{
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    enum FLACExtradataFormat format;
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    uint8_t *streaminfo;
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    FLACContext *s = avctx->priv_data;
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    s->avctx = avctx;
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    avctx->sample_fmt = SAMPLE_FMT_S16;
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    /* for now, the raw FLAC header is allowed to be passed to the decoder as
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       frame data instead of extradata. */
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    if (!avctx->extradata)
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        return 0;
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142
    if (!ff_flac_is_extradata_valid(avctx, &format, &streaminfo))
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        return -1;
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    /* initialize based on the demuxer-supplied streamdata header */
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    ff_flac_parse_streaminfo(avctx, (FLACStreaminfo *)s, streaminfo);
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    allocate_buffers(s);
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    s->got_streaminfo = 1;
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    return 0;
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}
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static void dump_headers(AVCodecContext *avctx, FLACStreaminfo *s)
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{
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    av_log(avctx, AV_LOG_DEBUG, "  Max Blocksize: %d\n", s->max_blocksize);
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    av_log(avctx, AV_LOG_DEBUG, "  Max Framesize: %d\n", s->max_framesize);
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    av_log(avctx, AV_LOG_DEBUG, "  Samplerate: %d\n", s->samplerate);
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    av_log(avctx, AV_LOG_DEBUG, "  Channels: %d\n", s->channels);
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    av_log(avctx, AV_LOG_DEBUG, "  Bits: %d\n", s->bps);
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}
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static void allocate_buffers(FLACContext *s)
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{
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    int i;
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    assert(s->max_blocksize);
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    if (s->max_framesize == 0 && s->max_blocksize) {
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        // FIXME header overhead
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        s->max_framesize= (s->channels * s->bps * s->max_blocksize + 7)/ 8;
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    }
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    for (i = 0; i < s->channels; i++) {
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        s->decoded[i] = av_realloc(s->decoded[i],
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                                   sizeof(int32_t)*s->max_blocksize);
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    }
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    if (s->allocated_bitstream_size < s->max_framesize)
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        s->bitstream= av_fast_realloc(s->bitstream,
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                                      &s->allocated_bitstream_size,
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                                      s->max_framesize);
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}
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void ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
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                              const uint8_t *buffer)
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{
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    GetBitContext gb;
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    init_get_bits(&gb, buffer, FLAC_STREAMINFO_SIZE*8);
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    skip_bits(&gb, 16); /* skip min blocksize */
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    s->max_blocksize = get_bits(&gb, 16);
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    if (s->max_blocksize < 16) {
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        av_log(avctx, AV_LOG_WARNING, "invalid max blocksize: %d\n",
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               s->max_blocksize);
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        s->max_blocksize = 16;
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    }
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    skip_bits(&gb, 24); /* skip min frame size */
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    s->max_framesize = get_bits_long(&gb, 24);
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    s->samplerate = get_bits_long(&gb, 20);
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    s->channels = get_bits(&gb, 3) + 1;
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    s->bps = get_bits(&gb, 5) + 1;
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    avctx->channels = s->channels;
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    avctx->sample_rate = s->samplerate;
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    avctx->bits_per_raw_sample = s->bps;
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    if (s->bps > 16)
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        avctx->sample_fmt = SAMPLE_FMT_S32;
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    else
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        avctx->sample_fmt = SAMPLE_FMT_S16;
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    s->samples  = get_bits_long(&gb, 32) << 4;
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    s->samples |= get_bits(&gb, 4);
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    skip_bits_long(&gb, 64); /* md5 sum */
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    skip_bits_long(&gb, 64); /* md5 sum */
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    dump_headers(avctx, s);
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}
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/**
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 * Parse a list of metadata blocks. This list of blocks must begin with
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 * the fLaC marker.
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 * @param s the flac decoding context containing the gb bit reader used to
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 *          parse metadata
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 * @return non-zero if metadata is invalid
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 */
229
static int metadata_parse(FLACContext *s)
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{
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    int i, metadata_last, metadata_type, metadata_size;
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    skip_bits_long(&s->gb, 32);
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    do {
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        metadata_last = get_bits1(&s->gb);
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        metadata_type = get_bits(&s->gb, 7);
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        metadata_size = get_bits_long(&s->gb, 24);
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        if (get_bits_count(&s->gb) + 8*metadata_size > s->gb.size_in_bits) {
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            /* need more data. reset the bitstream reader and return. */
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            init_get_bits(&s->gb, s->gb.buffer, s->gb.size_in_bits);
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            break;
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        }
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        if (metadata_size) {
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            switch (metadata_type) {
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            case FLAC_METADATA_TYPE_STREAMINFO:
249
                if (!s->got_streaminfo) {
250
                    ff_flac_parse_streaminfo(s->avctx, (FLACStreaminfo *)s,
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                                             s->gb.buffer+get_bits_count(&s->gb)/8);
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                    allocate_buffers(s);
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                    s->got_streaminfo = 1;
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                }
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            default:
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                for (i = 0; i < metadata_size; i++)
257
                    skip_bits(&s->gb, 8);
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            }
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        }
260
    } while (!metadata_last);
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262
    return 0;
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}
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265
static int decode_residuals(FLACContext *s, int channel, int pred_order)
266
{
267
    int i, tmp, partition, method_type, rice_order;
268
    int sample = 0, samples;
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270
    method_type = get_bits(&s->gb, 2);
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    if (method_type > 1) {
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        av_log(s->avctx, AV_LOG_ERROR, "illegal residual coding method %d\n",
273
               method_type);
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        return -1;
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    }
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    rice_order = get_bits(&s->gb, 4);
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    samples= s->blocksize >> rice_order;
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    if (pred_order > samples) {
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        av_log(s->avctx, AV_LOG_ERROR, "invalid predictor order: %i > %i\n",
282
               pred_order, samples);
283 5484dad7 Reimar Döffinger
        return -1;
284
    }
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    sample=
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    i= pred_order;
288 1bec121f Justin Ruggles
    for (partition = 0; partition < (1 << rice_order); partition++) {
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        tmp = get_bits(&s->gb, method_type == 0 ? 4 : 5);
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        if (tmp == (method_type == 0 ? 15 : 31)) {
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            tmp = get_bits(&s->gb, 5);
292
            for (; i < samples; i++, sample++)
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                s->decoded[channel][sample] = get_sbits_long(&s->gb, tmp);
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        } else {
295
            for (; i < samples; i++, sample++) {
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                s->decoded[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
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            }
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        }
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        i= 0;
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    }
301
302
    return 0;
303 115329f1 Diego Biurrun
}
304 4f52c312 Michael Niedermayer
305
static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
306
{
307 08965b22 Loren Merritt
    const int blocksize = s->blocksize;
308
    int32_t *decoded = s->decoded[channel];
309 7846418b Patrik Kullman
    int av_uninit(a), av_uninit(b), av_uninit(c), av_uninit(d), i;
310 115329f1 Diego Biurrun
311 4f52c312 Michael Niedermayer
    /* warm up samples */
312 1bec121f Justin Ruggles
    for (i = 0; i < pred_order; i++) {
313 9de6e090 Justin Ruggles
        decoded[i] = get_sbits_long(&s->gb, s->curr_bps);
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    }
315 115329f1 Diego Biurrun
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    if (decode_residuals(s, channel, pred_order) < 0)
317
        return -1;
318
319 1bec121f Justin Ruggles
    if (pred_order > 0)
320 1f4fa6a4 Ramiro Polla
        a = decoded[pred_order-1];
321 1bec121f Justin Ruggles
    if (pred_order > 1)
322 1f4fa6a4 Ramiro Polla
        b = a - decoded[pred_order-2];
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    if (pred_order > 2)
324 1f4fa6a4 Ramiro Polla
        c = b - decoded[pred_order-2] + decoded[pred_order-3];
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    if (pred_order > 3)
326 1f4fa6a4 Ramiro Polla
        d = c - decoded[pred_order-2] + 2*decoded[pred_order-3] - decoded[pred_order-4];
327 08965b22 Loren Merritt
328 1bec121f Justin Ruggles
    switch (pred_order) {
329
    case 0:
330
        break;
331
    case 1:
332
        for (i = pred_order; i < blocksize; i++)
333
            decoded[i] = a += decoded[i];
334
        break;
335
    case 2:
336
        for (i = pred_order; i < blocksize; i++)
337
            decoded[i] = a += b += decoded[i];
338
        break;
339
    case 3:
340
        for (i = pred_order; i < blocksize; i++)
341
            decoded[i] = a += b += c += decoded[i];
342
        break;
343
    case 4:
344
        for (i = pred_order; i < blocksize; i++)
345
            decoded[i] = a += b += c += d += decoded[i];
346
        break;
347
    default:
348
        av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);
349
        return -1;
350 4f52c312 Michael Niedermayer
    }
351 ac2570a8 Michael Niedermayer
352 4f52c312 Michael Niedermayer
    return 0;
353
}
354
355
static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
356
{
357 0187178e Luca Barbato
    int i, j;
358 4f52c312 Michael Niedermayer
    int coeff_prec, qlevel;
359
    int coeffs[pred_order];
360 d1a5c421 Loren Merritt
    int32_t *decoded = s->decoded[channel];
361 115329f1 Diego Biurrun
362 4f52c312 Michael Niedermayer
    /* warm up samples */
363 1bec121f Justin Ruggles
    for (i = 0; i < pred_order; i++) {
364 9de6e090 Justin Ruggles
        decoded[i] = get_sbits_long(&s->gb, s->curr_bps);
365 4f52c312 Michael Niedermayer
    }
366 115329f1 Diego Biurrun
367 4f52c312 Michael Niedermayer
    coeff_prec = get_bits(&s->gb, 4) + 1;
368 1bec121f Justin Ruggles
    if (coeff_prec == 16) {
369 5305f40b Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "invalid coeff precision\n");
370 4f52c312 Michael Niedermayer
        return -1;
371
    }
372 ac2570a8 Michael Niedermayer
    qlevel = get_sbits(&s->gb, 5);
373 1bec121f Justin Ruggles
    if (qlevel < 0) {
374 9f3d3ecf Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "qlevel %d not supported, maybe buggy stream\n",
375
               qlevel);
376 9d656110 Michael Niedermayer
        return -1;
377
    }
378
379 1bec121f Justin Ruggles
    for (i = 0; i < pred_order; i++) {
380 ac2570a8 Michael Niedermayer
        coeffs[i] = get_sbits(&s->gb, coeff_prec);
381 4f52c312 Michael Niedermayer
    }
382 115329f1 Diego Biurrun
383 4f52c312 Michael Niedermayer
    if (decode_residuals(s, channel, pred_order) < 0)
384
        return -1;
385
386 0187178e Luca Barbato
    if (s->bps > 16) {
387
        int64_t sum;
388 1bec121f Justin Ruggles
        for (i = pred_order; i < s->blocksize; i++) {
389 0187178e Luca Barbato
            sum = 0;
390
            for (j = 0; j < pred_order; j++)
391 d1a5c421 Loren Merritt
                sum += (int64_t)coeffs[j] * decoded[i-j-1];
392
            decoded[i] += sum >> qlevel;
393 0187178e Luca Barbato
        }
394
    } else {
395 1bec121f Justin Ruggles
        for (i = pred_order; i < s->blocksize-1; i += 2) {
396 d1a5c421 Loren Merritt
            int c;
397
            int d = decoded[i-pred_order];
398
            int s0 = 0, s1 = 0;
399 1bec121f Justin Ruggles
            for (j = pred_order-1; j > 0; j--) {
400 d1a5c421 Loren Merritt
                c = coeffs[j];
401 bd49d4fd Loren Merritt
                s0 += c*d;
402 d1a5c421 Loren Merritt
                d = decoded[i-j];
403
                s1 += c*d;
404 bd49d4fd Loren Merritt
            }
405 d1a5c421 Loren Merritt
            c = coeffs[0];
406
            s0 += c*d;
407
            d = decoded[i] += s0 >> qlevel;
408
            s1 += c*d;
409
            decoded[i+1] += s1 >> qlevel;
410 bd49d4fd Loren Merritt
        }
411 1bec121f Justin Ruggles
        if (i < s->blocksize) {
412 bd49d4fd Loren Merritt
            int sum = 0;
413 0187178e Luca Barbato
            for (j = 0; j < pred_order; j++)
414 d1a5c421 Loren Merritt
                sum += coeffs[j] * decoded[i-j-1];
415
            decoded[i] += sum >> qlevel;
416 0187178e Luca Barbato
        }
417 4f52c312 Michael Niedermayer
    }
418 115329f1 Diego Biurrun
419 4f52c312 Michael Niedermayer
    return 0;
420
}
421
422
static inline int decode_subframe(FLACContext *s, int channel)
423
{
424
    int type, wasted = 0;
425
    int i, tmp;
426 115329f1 Diego Biurrun
427 4f52c312 Michael Niedermayer
    s->curr_bps = s->bps;
428 1bec121f Justin Ruggles
    if (channel == 0) {
429
        if (s->decorrelation == RIGHT_SIDE)
430 ac2570a8 Michael Niedermayer
            s->curr_bps++;
431 1bec121f Justin Ruggles
    } else {
432
        if (s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
433 ac2570a8 Michael Niedermayer
            s->curr_bps++;
434
    }
435
436 1bec121f Justin Ruggles
    if (get_bits1(&s->gb)) {
437 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");
438 4f52c312 Michael Niedermayer
        return -1;
439
    }
440
    type = get_bits(&s->gb, 6);
441 c5706efd Justin Ruggles
442 1bec121f Justin Ruggles
    if (get_bits1(&s->gb)) {
443 4f52c312 Michael Niedermayer
        wasted = 1;
444
        while (!get_bits1(&s->gb))
445
            wasted++;
446
        s->curr_bps -= wasted;
447
    }
448 a3d2379b Justin Ruggles
    if (s->curr_bps > 32) {
449
        ff_log_missing_feature(s->avctx, "decorrelated bit depth > 32", 0);
450
        return -1;
451
    }
452 c5706efd Justin Ruggles
453 ac2570a8 Michael Niedermayer
//FIXME use av_log2 for types
454 1bec121f Justin Ruggles
    if (type == 0) {
455 9de6e090 Justin Ruggles
        tmp = get_sbits_long(&s->gb, s->curr_bps);
456 4f52c312 Michael Niedermayer
        for (i = 0; i < s->blocksize; i++)
457
            s->decoded[channel][i] = tmp;
458 1bec121f Justin Ruggles
    } else if (type == 1) {
459 4f52c312 Michael Niedermayer
        for (i = 0; i < s->blocksize; i++)
460 9de6e090 Justin Ruggles
            s->decoded[channel][i] = get_sbits_long(&s->gb, s->curr_bps);
461 1bec121f Justin Ruggles
    } else if ((type >= 8) && (type <= 12)) {
462 4f52c312 Michael Niedermayer
        if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
463
            return -1;
464 1bec121f Justin Ruggles
    } else if (type >= 32) {
465 4f52c312 Michael Niedermayer
        if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
466
            return -1;
467 1bec121f Justin Ruggles
    } else {
468 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
469 4f52c312 Michael Niedermayer
        return -1;
470
    }
471 115329f1 Diego Biurrun
472 1bec121f Justin Ruggles
    if (wasted) {
473 4f52c312 Michael Niedermayer
        int i;
474
        for (i = 0; i < s->blocksize; i++)
475
            s->decoded[channel][i] <<= wasted;
476
    }
477
478
    return 0;
479
}
480
481 ac66834c Michael Niedermayer
static int decode_frame(FLACContext *s, int alloc_data_size)
482 4f52c312 Michael Niedermayer
{
483 9d656110 Michael Niedermayer
    int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8;
484 0496a034 Michael Niedermayer
    int decorrelation, bps, blocksize, samplerate;
485 115329f1 Diego Biurrun
486 4f52c312 Michael Niedermayer
    blocksize_code = get_bits(&s->gb, 4);
487
488
    sample_rate_code = get_bits(&s->gb, 4);
489 115329f1 Diego Biurrun
490 4f52c312 Michael Niedermayer
    assignment = get_bits(&s->gb, 4); /* channel assignment */
491 0496a034 Michael Niedermayer
    if (assignment < 8 && s->channels == assignment+1)
492
        decorrelation = INDEPENDENT;
493
    else if (assignment >=8 && assignment < 11 && s->channels == 2)
494
        decorrelation = LEFT_SIDE + assignment - 8;
495 1bec121f Justin Ruggles
    else {
496 9f3d3ecf Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n",
497
               assignment, s->channels);
498 4f52c312 Michael Niedermayer
        return -1;
499
    }
500 115329f1 Diego Biurrun
501 4f52c312 Michael Niedermayer
    sample_size_code = get_bits(&s->gb, 3);
502 1bec121f Justin Ruggles
    if (sample_size_code == 0)
503 0496a034 Michael Niedermayer
        bps= s->bps;
504 1bec121f Justin Ruggles
    else if ((sample_size_code != 3) && (sample_size_code != 7))
505 0496a034 Michael Niedermayer
        bps = sample_size_table[sample_size_code];
506 1bec121f Justin Ruggles
    else {
507 9f3d3ecf Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n",
508
               sample_size_code);
509 4f52c312 Michael Niedermayer
        return -1;
510
    }
511 82159ad9 Justin Ruggles
    if (bps > 16) {
512
        s->avctx->sample_fmt = SAMPLE_FMT_S32;
513
        s->sample_shift = 32 - bps;
514
        s->is32 = 1;
515
    } else {
516
        s->avctx->sample_fmt = SAMPLE_FMT_S16;
517
        s->sample_shift = 16 - bps;
518
        s->is32 = 0;
519
    }
520
    s->bps = s->avctx->bits_per_raw_sample = bps;
521 4f52c312 Michael Niedermayer
522 1bec121f Justin Ruggles
    if (get_bits1(&s->gb)) {
523 1cef211d Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
524 0496a034 Michael Niedermayer
        return -1;
525 4f52c312 Michael Niedermayer
    }
526 115329f1 Diego Biurrun
527 1bec121f Justin Ruggles
    if (get_utf8(&s->gb) < 0) {
528 0496a034 Michael Niedermayer
        av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
529
        return -1;
530
    }
531 115329f1 Diego Biurrun
532 dde318d5 Justin Ruggles
    if (blocksize_code == 0) {
533
        av_log(s->avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n");
534
        return -1;
535
    } else if (blocksize_code == 6)
536 0496a034 Michael Niedermayer
        blocksize = get_bits(&s->gb, 8)+1;
537 ac2570a8 Michael Niedermayer
    else if (blocksize_code == 7)
538 0496a034 Michael Niedermayer
        blocksize = get_bits(&s->gb, 16)+1;
539 115329f1 Diego Biurrun
    else
540 0496a034 Michael Niedermayer
        blocksize = blocksize_table[blocksize_code];
541 4f52c312 Michael Niedermayer
542 1bec121f Justin Ruggles
    if (blocksize > s->max_blocksize) {
543 9f3d3ecf Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize,
544
               s->max_blocksize);
545 ac2570a8 Michael Niedermayer
        return -1;
546
    }
547
548 549bccdb Justin Ruggles
    if (blocksize * s->channels * (s->is32 ? 4 : 2) > alloc_data_size)
549 ac66834c Michael Niedermayer
        return -1;
550
551 1bec121f Justin Ruggles
    if (sample_rate_code == 0)
552 0496a034 Michael Niedermayer
        samplerate= s->samplerate;
553 1bec121f Justin Ruggles
    else if (sample_rate_code < 12)
554 0496a034 Michael Niedermayer
        samplerate = sample_rate_table[sample_rate_code];
555 ac2570a8 Michael Niedermayer
    else if (sample_rate_code == 12)
556 0496a034 Michael Niedermayer
        samplerate = get_bits(&s->gb, 8) * 1000;
557 ac2570a8 Michael Niedermayer
    else if (sample_rate_code == 13)
558 0496a034 Michael Niedermayer
        samplerate = get_bits(&s->gb, 16);
559 ac2570a8 Michael Niedermayer
    else if (sample_rate_code == 14)
560 0496a034 Michael Niedermayer
        samplerate = get_bits(&s->gb, 16) * 10;
561 1bec121f Justin Ruggles
    else {
562 9f3d3ecf Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n",
563
               sample_rate_code);
564 ac2570a8 Michael Niedermayer
        return -1;
565 4f52c312 Michael Niedermayer
    }
566
567 9d656110 Michael Niedermayer
    skip_bits(&s->gb, 8);
568 3abe5fbd Aurelien Jacobs
    crc8 = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0,
569
                  s->gb.buffer, get_bits_count(&s->gb)/8);
570 1bec121f Justin Ruggles
    if (crc8) {
571 160d679c Mike Melanson
        av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8);
572 9d656110 Michael Niedermayer
        return -1;
573
    }
574 115329f1 Diego Biurrun
575 0496a034 Michael Niedermayer
    s->blocksize    = blocksize;
576
    s->samplerate   = samplerate;
577
    s->bps          = bps;
578
    s->decorrelation= decorrelation;
579 4f52c312 Michael Niedermayer
580 9482171b Justin Ruggles
//    dump_headers(s->avctx, (FLACStreaminfo *)s);
581 4f52c312 Michael Niedermayer
582
    /* subframes */
583 1bec121f Justin Ruggles
    for (i = 0; i < s->channels; i++) {
584 4f52c312 Michael Niedermayer
        if (decode_subframe(s, i) < 0)
585
            return -1;
586
    }
587 115329f1 Diego Biurrun
588 4f52c312 Michael Niedermayer
    align_get_bits(&s->gb);
589
590
    /* frame footer */
591
    skip_bits(&s->gb, 16); /* data crc */
592
593
    return 0;
594
}
595
596
static int flac_decode_frame(AVCodecContext *avctx,
597
                            void *data, int *data_size,
598 1545c5e5 Michael Niedermayer
                            const uint8_t *buf, int buf_size)
599 4f52c312 Michael Niedermayer
{
600
    FLACContext *s = avctx->priv_data;
601 c5199729 Justin Ruggles
    int tmp = 0, i, j = 0, input_buf_size = 0, bytes_read = 0;
602 82159ad9 Justin Ruggles
    int16_t *samples_16 = data;
603
    int32_t *samples_32 = data;
604 ac66834c Michael Niedermayer
    int alloc_data_size= *data_size;
605
606
    *data_size=0;
607 4f52c312 Michael Niedermayer
608 1bec121f Justin Ruggles
    if (s->max_framesize == 0) {
609 d3ce0792 Jai Menon
        s->max_framesize= FFMAX(4, buf_size); // should hopefully be enough for the first header
610 ac2570a8 Michael Niedermayer
        s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
611
    }
612
613 1bec121f Justin Ruggles
    if (1 && s->max_framesize) { //FIXME truncated
614 1df0390e Justin Ruggles
        if (s->bitstream_size < 4 || AV_RL32(s->bitstream) != MKTAG('f','L','a','C'))
615
            buf_size= FFMIN(buf_size, s->max_framesize - FFMIN(s->bitstream_size, s->max_framesize));
616
        input_buf_size= buf_size;
617 ac2570a8 Michael Niedermayer
618 1df0390e Justin Ruggles
        if (s->bitstream_size + buf_size < buf_size || s->bitstream_index + s->bitstream_size + buf_size < s->bitstream_index)
619
            return -1;
620 e0168e3b Michael Niedermayer
621 1df0390e Justin Ruggles
        if (s->allocated_bitstream_size < s->bitstream_size + buf_size)
622
            s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->bitstream_size + buf_size);
623 e0168e3b Michael Niedermayer
624 1df0390e Justin Ruggles
        if (s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size) {
625 9f3d3ecf Justin Ruggles
            memmove(s->bitstream, &s->bitstream[s->bitstream_index],
626
                    s->bitstream_size);
627 1df0390e Justin Ruggles
            s->bitstream_index=0;
628
        }
629 9f3d3ecf Justin Ruggles
        memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size],
630
               buf, buf_size);
631 1df0390e Justin Ruggles
        buf= &s->bitstream[s->bitstream_index];
632
        buf_size += s->bitstream_size;
633
        s->bitstream_size= buf_size;
634 115329f1 Diego Biurrun
635 1df0390e Justin Ruggles
        if (buf_size < s->max_framesize && input_buf_size) {
636
            return input_buf_size;
637
        }
638 ac2570a8 Michael Niedermayer
    }
639 4f52c312 Michael Niedermayer
640
    init_get_bits(&s->gb, buf, buf_size*8);
641 115329f1 Diego Biurrun
642 5ef4fa87 Justin Ruggles
    /* check that there is at least the smallest decodable amount of data.
643
       this amount corresponds to the smallest valid FLAC frame possible. */
644
    if (buf_size < 24)
645
        goto end;
646
647 55a72738 Justin Ruggles
    /* check for inline header */
648
    if (show_bits_long(&s->gb, 32) == MKBETAG('f','L','a','C')) {
649
        if (metadata_parse(s)) {
650
            av_log(s->avctx, AV_LOG_ERROR, "invalid header\n");
651
            return -1;
652
        }
653 2b4b8c82 Michael Niedermayer
        goto end;
654 55a72738 Justin Ruggles
    }
655 2b4b8c82 Michael Niedermayer
656 13de8a08 Justin Ruggles
    tmp = show_bits(&s->gb, 16);
657 1bec121f Justin Ruggles
    if ((tmp & 0xFFFE) != 0xFFF8) {
658 13de8a08 Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n");
659 1bec121f Justin Ruggles
        while (get_bits_count(&s->gb)/8+2 < buf_size && (show_bits(&s->gb, 16) & 0xFFFE) != 0xFFF8)
660 13de8a08 Justin Ruggles
            skip_bits(&s->gb, 8);
661
        goto end; // we may not have enough bits left to decode a frame, so try next time
662
    }
663
    skip_bits(&s->gb, 16);
664 1bec121f Justin Ruggles
    if (decode_frame(s, alloc_data_size) < 0) {
665 13de8a08 Justin Ruggles
        av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
666
        s->bitstream_size=0;
667
        s->bitstream_index=0;
668
        return -1;
669
    }
670 ac2570a8 Michael Niedermayer
671 c448303d Michael Niedermayer
#define DECORRELATE(left, right)\
672
            assert(s->channels == 2);\
673 1bec121f Justin Ruggles
            for (i = 0; i < s->blocksize; i++) {\
674 c448303d Michael Niedermayer
                int a= s->decoded[0][i];\
675
                int b= s->decoded[1][i];\
676 82159ad9 Justin Ruggles
                if (s->is32) {\
677
                    *samples_32++ = (left)  << s->sample_shift;\
678
                    *samples_32++ = (right) << s->sample_shift;\
679
                } else {\
680
                    *samples_16++ = (left)  << s->sample_shift;\
681
                    *samples_16++ = (right) << s->sample_shift;\
682
                }\
683 c448303d Michael Niedermayer
            }\
684
            break;
685
686 1bec121f Justin Ruggles
    switch (s->decorrelation) {
687
    case INDEPENDENT:
688
        for (j = 0; j < s->blocksize; j++) {
689 82159ad9 Justin Ruggles
            for (i = 0; i < s->channels; i++) {
690
                if (s->is32)
691
                    *samples_32++ = s->decoded[i][j] << s->sample_shift;
692
                else
693
                    *samples_16++ = s->decoded[i][j] << s->sample_shift;
694
            }
695 1bec121f Justin Ruggles
        }
696
        break;
697
    case LEFT_SIDE:
698
        DECORRELATE(a,a-b)
699
    case RIGHT_SIDE:
700
        DECORRELATE(a+b,b)
701
    case MID_SIDE:
702
        DECORRELATE( (a-=b>>1) + b, a)
703 4f52c312 Michael Niedermayer
    }
704
705 82159ad9 Justin Ruggles
    *data_size = s->blocksize * s->channels * (s->is32 ? 4 : 2);
706 4f52c312 Michael Niedermayer
707 ac2570a8 Michael Niedermayer
end:
708 c5199729 Justin Ruggles
    bytes_read = (get_bits_count(&s->gb)+7)/8;
709
    if (bytes_read > buf_size) {
710
        av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", bytes_read - buf_size);
711 9d656110 Michael Niedermayer
        s->bitstream_size=0;
712
        s->bitstream_index=0;
713 ac2570a8 Michael Niedermayer
        return -1;
714
    }
715 4f52c312 Michael Niedermayer
716 1bec121f Justin Ruggles
    if (s->bitstream_size) {
717 c5199729 Justin Ruggles
        s->bitstream_index += bytes_read;
718
        s->bitstream_size  -= bytes_read;
719 ac2570a8 Michael Niedermayer
        return input_buf_size;
720 1bec121f Justin Ruggles
    } else
721 c5199729 Justin Ruggles
        return bytes_read;
722 4f52c312 Michael Niedermayer
}
723
724 98a6fff9 Zuxy Meng
static av_cold int flac_decode_close(AVCodecContext *avctx)
725 4f52c312 Michael Niedermayer
{
726
    FLACContext *s = avctx->priv_data;
727
    int i;
728 115329f1 Diego Biurrun
729 1bec121f Justin Ruggles
    for (i = 0; i < s->channels; i++) {
730 ac2570a8 Michael Niedermayer
        av_freep(&s->decoded[i]);
731 4f52c312 Michael Niedermayer
    }
732 ac2570a8 Michael Niedermayer
    av_freep(&s->bitstream);
733 115329f1 Diego Biurrun
734 4f52c312 Michael Niedermayer
    return 0;
735
}
736
737 1bec121f Justin Ruggles
static void flac_flush(AVCodecContext *avctx)
738
{
739 1e31d32c Michael Niedermayer
    FLACContext *s = avctx->priv_data;
740
741
    s->bitstream_size=
742
    s->bitstream_index= 0;
743
}
744
745 4f52c312 Michael Niedermayer
AVCodec flac_decoder = {
746
    "flac",
747
    CODEC_TYPE_AUDIO,
748
    CODEC_ID_FLAC,
749
    sizeof(FLACContext),
750
    flac_decode_init,
751
    NULL,
752
    flac_decode_close,
753
    flac_decode_frame,
754 4c453ddb Michael Niedermayer
    CODEC_CAP_DELAY,
755 115329f1 Diego Biurrun
    .flush= flac_flush,
756 fe4bf374 Stefano Sabatini
    .long_name= NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
757 4f52c312 Michael Niedermayer
};