X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fflac.c;h=07da702e9495fc4f5afdc7f032e75ff8e45ed446;hb=e00eb03cd8bfb6993d33c30ccd560947b5f6bad5;hp=8bf00b2d047ce5c26788fdaae6f44f28b847b867;hpb=0187178e07218772553767da0cef12e0c0b149a6;p=ffmpeg

diff --git a/libavcodec/flac.c b/libavcodec/flac.c
index 8bf00b2d047..07da702e949 100644
--- a/libavcodec/flac.c
+++ b/libavcodec/flac.c
@@ -1,804 +1,245 @@
 /*
- * FLAC (Free Lossless Audio Codec) decoder
- * Copyright (c) 2003 Alex Beregszaszi
+ * FLAC common code
+ * Copyright (c) 2009 Justin Ruggles
  *
- * This library is free software; you can redistribute it and/or
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-/**
- * @file flac.c
- * FLAC (Free Lossless Audio Codec) decoder
- * @author Alex Beregszaszi
- *
- * For more information on the FLAC format, visit:
- *  http://flac.sourceforge.net/
- *
- * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
- * through, starting from the initial 'fLaC' signature; or by passing the
- * 34-byte streaminfo structure through avctx->extradata[_size] followed
- * by data starting with the 0xFFF8 marker.
- */
-
-#include <limits.h>
-
-#include "avcodec.h"
-#include "bitstream.h"
-#include "golomb.h"
-#include "crc.h"
-
-#undef NDEBUG
-#include <assert.h>
-
-#define MAX_CHANNELS 8
-#define MAX_BLOCKSIZE 65535
-#define FLAC_STREAMINFO_SIZE 34
-
-enum decorrelation_type {
-    INDEPENDENT,
-    LEFT_SIDE,
-    RIGHT_SIDE,
-    MID_SIDE,
-};
-
-typedef struct FLACContext {
-    AVCodecContext *avctx;
-    GetBitContext gb;
-
-    int min_blocksize, max_blocksize;
-    int min_framesize, max_framesize;
-    int samplerate, channels;
-    int blocksize/*, last_blocksize*/;
-    int bps, curr_bps;
-    enum decorrelation_type decorrelation;
-
-    int32_t *decoded[MAX_CHANNELS];
-    uint8_t *bitstream;
-    int bitstream_size;
-    int bitstream_index;
-    unsigned int allocated_bitstream_size;
-} FLACContext;
-
-#define METADATA_TYPE_STREAMINFO 0
-
-static int sample_rate_table[] =
-{ 0, 0, 0, 0,
-  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
-  0, 0, 0, 0 };
-
-static int sample_size_table[] =
-{ 0, 8, 12, 0, 16, 20, 24, 0 };
-
-static int blocksize_table[] = {
-     0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
-256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
+#include "libavutil/audioconvert.h"
+#include "libavutil/crc.h"
+#include "libavutil/log.h"
+#include "bytestream.h"
+#include "get_bits.h"
+#include "flac.h"
+#include "flacdata.h"
+
+static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 };
+
+static const int64_t flac_channel_layouts[6] = {
+    AV_CH_LAYOUT_MONO,
+    AV_CH_LAYOUT_STEREO,
+    AV_CH_LAYOUT_SURROUND,
+    AV_CH_LAYOUT_QUAD,
+    AV_CH_LAYOUT_5POINT0,
+    AV_CH_LAYOUT_5POINT1
 };
 
 static int64_t get_utf8(GetBitContext *gb)
 {
-    uint64_t val;
-    int ones=0, bytes;
-
-    while(get_bits1(gb))
-        ones++;
-
-    if     (ones==0) bytes=0;
-    else if(ones==1) return -1;
-    else             bytes= ones - 1;
-
-    val= get_bits(gb, 7-ones);
-    while(bytes--){
-        const int tmp = get_bits(gb, 8);
-
-        if((tmp>>6) != 2)
-            return -1;
-        val<<=6;
-        val|= tmp&0x3F;
-    }
+    int64_t val;
+    GET_UTF8(val, get_bits(gb, 8), return -1;)
     return val;
 }
 
-#if 0
-static int skip_utf8(GetBitContext *gb)
+int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
+                                FLACFrameInfo *fi, int log_level_offset)
 {
-    int ones=0, bytes;
+    int bs_code, sr_code, bps_code;
 
-    while(get_bits1(gb))
-        ones++;
-
-    if     (ones==0) bytes=0;
-    else if(ones==1) return -1;
-    else             bytes= ones - 1;
-
-    skip_bits(gb, 7-ones);
-    while(bytes--){
-        const int tmp = get_bits(gb, 8);
-
-        if((tmp>>6) != 2)
-            return -1;
-    }
-    return 0;
-}
-#endif
-
-static void metadata_streaminfo(FLACContext *s);
-static void dump_headers(FLACContext *s);
-
-static int flac_decode_init(AVCodecContext * avctx)
-{
-    FLACContext *s = avctx->priv_data;
-    s->avctx = avctx;
-
-    /* initialize based on the demuxer-supplied streamdata header */
-    if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {
-        init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);
-        metadata_streaminfo(s);
-        dump_headers(s);
-    }
-
-    return 0;
-}
-
-static void dump_headers(FLACContext *s)
-{
-    av_log(s->avctx, AV_LOG_DEBUG, "  Blocksize: %d .. %d (%d)\n", s->min_blocksize, s->max_blocksize, s->blocksize);
-    av_log(s->avctx, AV_LOG_DEBUG, "  Framesize: %d .. %d\n", s->min_framesize, s->max_framesize);
-    av_log(s->avctx, AV_LOG_DEBUG, "  Samplerate: %d\n", s->samplerate);
-    av_log(s->avctx, AV_LOG_DEBUG, "  Channels: %d\n", s->channels);
-    av_log(s->avctx, AV_LOG_DEBUG, "  Bits: %d\n", s->bps);
-}
-
-static void allocate_buffers(FLACContext *s){
-    int i;
-
-    assert(s->max_blocksize);
-
-    if(s->max_framesize == 0 && s->max_blocksize){
-        s->max_framesize= (s->channels * s->bps * s->max_blocksize + 7)/ 8; //FIXME header overhead
-    }
-
-    for (i = 0; i < s->channels; i++)
-    {
-        s->decoded[i] = av_realloc(s->decoded[i], sizeof(int32_t)*s->max_blocksize);
-    }
-
-    s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
-}
-
-static void metadata_streaminfo(FLACContext *s)
-{
-    /* mandatory streaminfo */
-    s->min_blocksize = get_bits(&s->gb, 16);
-    s->max_blocksize = get_bits(&s->gb, 16);
-
-    s->min_framesize = get_bits_long(&s->gb, 24);
-    s->max_framesize = get_bits_long(&s->gb, 24);
-
-    s->samplerate = get_bits_long(&s->gb, 20);
-    s->channels = get_bits(&s->gb, 3) + 1;
-    s->bps = get_bits(&s->gb, 5) + 1;
-
-    s->avctx->channels = s->channels;
-    s->avctx->sample_rate = s->samplerate;
-
-    skip_bits(&s->gb, 36); /* total num of samples */
-
-    skip_bits(&s->gb, 64); /* md5 sum */
-    skip_bits(&s->gb, 64); /* md5 sum */
-
-    allocate_buffers(s);
-}
-
-static int decode_residuals(FLACContext *s, int channel, int pred_order)
-{
-    int i, tmp, partition, method_type, rice_order;
-    int sample = 0, samples;
-
-    method_type = get_bits(&s->gb, 2);
-    if (method_type != 0){
-        av_log(s->avctx, AV_LOG_DEBUG, "illegal residual coding method %d\n", method_type);
+    /* frame sync code */
+    if ((get_bits(gb, 15) & 0x7FFF) != 0x7FFC) {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset, "invalid sync code\n");
         return -1;
     }
 
-    rice_order = get_bits(&s->gb, 4);
-
-    samples= s->blocksize >> rice_order;
+    /* variable block size stream code */
+    fi->is_var_size = get_bits1(gb);
 
-    sample=
-    i= pred_order;
-    for (partition = 0; partition < (1 << rice_order); partition++)
-    {
-        tmp = get_bits(&s->gb, 4);
-        if (tmp == 15)
-        {
-            av_log(s->avctx, AV_LOG_DEBUG, "fixed len partition\n");
-            tmp = get_bits(&s->gb, 5);
-            for (; i < samples; i++, sample++)
-                s->decoded[channel][sample] = get_sbits(&s->gb, tmp);
-        }
-        else
-        {
-//            av_log(s->avctx, AV_LOG_DEBUG, "rice coded partition k=%d\n", tmp);
-            for (; i < samples; i++, sample++){
-                s->decoded[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
-            }
-        }
-        i= 0;
-    }
+    /* block size and sample rate codes */
+    bs_code = get_bits(gb, 4);
+    sr_code = get_bits(gb, 4);
 
-//    av_log(s->avctx, AV_LOG_DEBUG, "partitions: %d, samples: %d\n", 1 << rice_order, sample);
-
-    return 0;
-}
-
-static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order)
-{
-    int i;
-
-//    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME FIXED\n");
-
-    /* warm up samples */
-//    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);
-
-    for (i = 0; i < pred_order; i++)
-    {
-        s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
-//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, s->decoded[channel][i]);
-    }
-
-    if (decode_residuals(s, channel, pred_order) < 0)
+    /* channels and decorrelation */
+    fi->ch_mode = get_bits(gb, 4);
+    if (fi->ch_mode < FLAC_MAX_CHANNELS) {
+        fi->channels = fi->ch_mode + 1;
+        fi->ch_mode = FLAC_CHMODE_INDEPENDENT;
+    } else if (fi->ch_mode < FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE) {
+        fi->channels = 2;
+        fi->ch_mode -= FLAC_MAX_CHANNELS - 1;
+    } else {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "invalid channel mode: %d\n", fi->ch_mode);
         return -1;
-
-    switch(pred_order)
-    {
-        case 0:
-            break;
-        case 1:
-            for (i = pred_order; i < s->blocksize; i++)
-                s->decoded[channel][i] +=   s->decoded[channel][i-1];
-            break;
-        case 2:
-            for (i = pred_order; i < s->blocksize; i++)
-                s->decoded[channel][i] += 2*s->decoded[channel][i-1]
-                                          - s->decoded[channel][i-2];
-            break;
-        case 3:
-            for (i = pred_order; i < s->blocksize; i++)
-                s->decoded[channel][i] += 3*s->decoded[channel][i-1]
-                                        - 3*s->decoded[channel][i-2]
-                                        +   s->decoded[channel][i-3];
-            break;
-        case 4:
-            for (i = pred_order; i < s->blocksize; i++)
-                s->decoded[channel][i] += 4*s->decoded[channel][i-1]
-                                        - 6*s->decoded[channel][i-2]
-                                        + 4*s->decoded[channel][i-3]
-                                        -   s->decoded[channel][i-4];
-            break;
-        default:
-            av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);
-            return -1;
-    }
-
-    return 0;
-}
-
-static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
-{
-    int i, j;
-    int coeff_prec, qlevel;
-    int coeffs[pred_order];
-
-//    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME LPC\n");
-
-    /* warm up samples */
-//    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);
-
-    for (i = 0; i < pred_order; i++)
-    {
-        s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
-//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, s->decoded[channel][i]);
     }
 
-    coeff_prec = get_bits(&s->gb, 4) + 1;
-    if (coeff_prec == 16)
-    {
-        av_log(s->avctx, AV_LOG_DEBUG, "invalid coeff precision\n");
+    /* bits per sample */
+    bps_code = get_bits(gb, 3);
+    if (bps_code == 3 || bps_code == 7) {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "invalid sample size code (%d)\n",
+               bps_code);
         return -1;
     }
-//    av_log(s->avctx, AV_LOG_DEBUG, "   qlp coeff prec: %d\n", coeff_prec);
-    qlevel = get_sbits(&s->gb, 5);
-//    av_log(s->avctx, AV_LOG_DEBUG, "   quant level: %d\n", qlevel);
-    if(qlevel < 0){
-        av_log(s->avctx, AV_LOG_DEBUG, "qlevel %d not supported, maybe buggy stream\n", qlevel);
+    fi->bps = sample_size_table[bps_code];
+
+    /* reserved bit */
+    if (get_bits1(gb)) {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "broken stream, invalid padding\n");
         return -1;
     }
 
-    for (i = 0; i < pred_order; i++)
-    {
-        coeffs[i] = get_sbits(&s->gb, coeff_prec);
-//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, coeffs[i]);
+    /* sample or frame count */
+    fi->frame_or_sample_num = get_utf8(gb);
+    if (fi->frame_or_sample_num < 0) {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "sample/frame number invalid; utf8 fscked\n");
+        return -1;
     }
 
-    if (decode_residuals(s, channel, pred_order) < 0)
+    /* blocksize */
+    if (bs_code == 0) {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "reserved blocksize code: 0\n");
         return -1;
-
-    if (s->bps > 16) {
-        int64_t sum;
-        for (i = pred_order; i < s->blocksize; i++)
-        {
-            sum = 0;
-            for (j = 0; j < pred_order; j++)
-                sum += (int64_t)coeffs[j] * s->decoded[channel][i-j-1];
-            s->decoded[channel][i] += sum >> qlevel;
-        }
+    } else if (bs_code == 6) {
+        fi->blocksize = get_bits(gb, 8) + 1;
+    } else if (bs_code == 7) {
+        fi->blocksize = get_bits(gb, 16) + 1;
     } else {
-        int sum;
-        for (i = pred_order; i < s->blocksize; i++)
-        {
-            sum = 0;
-            for (j = 0; j < pred_order; j++)
-                sum += coeffs[j] * s->decoded[channel][i-j-1];
-            s->decoded[channel][i] += sum >> qlevel;
-        }
-    }
-
-    return 0;
-}
-
-static inline int decode_subframe(FLACContext *s, int channel)
-{
-    int type, wasted = 0;
-    int i, tmp;
-
-    s->curr_bps = s->bps;
-    if(channel == 0){
-        if(s->decorrelation == RIGHT_SIDE)
-            s->curr_bps++;
-    }else{
-        if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
-            s->curr_bps++;
-    }
-
-    if (get_bits1(&s->gb))
-    {
-        av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");
+        fi->blocksize = ff_flac_blocksize_table[bs_code];
+    }
+
+    /* sample rate */
+    if (sr_code < 12) {
+        fi->samplerate = ff_flac_sample_rate_table[sr_code];
+    } else if (sr_code == 12) {
+        fi->samplerate = get_bits(gb, 8) * 1000;
+    } else if (sr_code == 13) {
+        fi->samplerate = get_bits(gb, 16);
+    } else if (sr_code == 14) {
+        fi->samplerate = get_bits(gb, 16) * 10;
+    } else {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "illegal sample rate code %d\n",
+               sr_code);
         return -1;
     }
-    type = get_bits(&s->gb, 6);
-//    wasted = get_bits1(&s->gb);
 
-//    if (wasted)
-//    {
-//        while (!get_bits1(&s->gb))
-//            wasted++;
-//        if (wasted)
-//            wasted++;
-//        s->curr_bps -= wasted;
-//    }
-#if 0
-    wasted= 16 - av_log2(show_bits(&s->gb, 17));
-    skip_bits(&s->gb, wasted+1);
-    s->curr_bps -= wasted;
-#else
-    if (get_bits1(&s->gb))
-    {
-        wasted = 1;
-        while (!get_bits1(&s->gb))
-            wasted++;
-        s->curr_bps -= wasted;
-        av_log(s->avctx, AV_LOG_DEBUG, "%d wasted bits\n", wasted);
-    }
-#endif
-//FIXME use av_log2 for types
-    if (type == 0)
-    {
-        av_log(s->avctx, AV_LOG_DEBUG, "coding type: constant\n");
-        tmp = get_sbits(&s->gb, s->curr_bps);
-        for (i = 0; i < s->blocksize; i++)
-            s->decoded[channel][i] = tmp;
-    }
-    else if (type == 1)
-    {
-        av_log(s->avctx, AV_LOG_DEBUG, "coding type: verbatim\n");
-        for (i = 0; i < s->blocksize; i++)
-            s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);
-    }
-    else if ((type >= 8) && (type <= 12))
-    {
-//        av_log(s->avctx, AV_LOG_DEBUG, "coding type: fixed\n");
-        if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
-            return -1;
-    }
-    else if (type >= 32)
-    {
-//        av_log(s->avctx, AV_LOG_DEBUG, "coding type: lpc\n");
-        if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
-            return -1;
-    }
-    else
-    {
-        av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
+    /* header CRC-8 check */
+    skip_bits(gb, 8);
+    if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer,
+               get_bits_count(gb)/8)) {
+        av_log(avctx, AV_LOG_ERROR + log_level_offset,
+               "header crc mismatch\n");
         return -1;
     }
 
-    if (wasted)
-    {
-        int i;
-        for (i = 0; i < s->blocksize; i++)
-            s->decoded[channel][i] <<= wasted;
-    }
-
     return 0;
 }
 
-static int decode_frame(FLACContext *s)
+int ff_flac_get_max_frame_size(int blocksize, int ch, int bps)
 {
-    int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8;
-    int decorrelation, bps, blocksize, samplerate;
-
-    blocksize_code = get_bits(&s->gb, 4);
-
-    sample_rate_code = get_bits(&s->gb, 4);
-
-    assignment = get_bits(&s->gb, 4); /* channel assignment */
-    if (assignment < 8 && s->channels == assignment+1)
-        decorrelation = INDEPENDENT;
-    else if (assignment >=8 && assignment < 11 && s->channels == 2)
-        decorrelation = LEFT_SIDE + assignment - 8;
-    else
-    {
-        av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n", assignment, s->channels);
-        return -1;
-    }
-
-    sample_size_code = get_bits(&s->gb, 3);
-    if(sample_size_code == 0)
-        bps= s->bps;
-    else if((sample_size_code != 3) && (sample_size_code != 7))
-        bps = sample_size_table[sample_size_code];
-    else
-    {
-        av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n", sample_size_code);
-        return -1;
-    }
-
-    if (get_bits1(&s->gb))
-    {
-        av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
-        return -1;
-    }
-
-    if(get_utf8(&s->gb) < 0){
-        av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
-        return -1;
-    }
-#if 0
-    if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
-        (s->min_blocksize != s->max_blocksize)){
-    }else{
-    }
-#endif
-
-    if (blocksize_code == 0)
-        blocksize = s->min_blocksize;
-    else if (blocksize_code == 6)
-        blocksize = get_bits(&s->gb, 8)+1;
-    else if (blocksize_code == 7)
-        blocksize = get_bits(&s->gb, 16)+1;
-    else
-        blocksize = blocksize_table[blocksize_code];
-
-    if(blocksize > s->max_blocksize){
-        av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize, s->max_blocksize);
-        return -1;
-    }
-
-    if (sample_rate_code == 0){
-        samplerate= s->samplerate;
-    }else if ((sample_rate_code > 3) && (sample_rate_code < 12))
-        samplerate = sample_rate_table[sample_rate_code];
-    else if (sample_rate_code == 12)
-        samplerate = get_bits(&s->gb, 8) * 1000;
-    else if (sample_rate_code == 13)
-        samplerate = get_bits(&s->gb, 16);
-    else if (sample_rate_code == 14)
-        samplerate = get_bits(&s->gb, 16) * 10;
-    else{
-        av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n", sample_rate_code);
-        return -1;
-    }
-
-    skip_bits(&s->gb, 8);
-    crc8= av_crc(av_crc07, 0, s->gb.buffer, get_bits_count(&s->gb)/8);
-    if(crc8){
-        av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8);
-        return -1;
-    }
+    /* Technically, there is no limit to FLAC frame size, but an encoder
+       should not write a frame that is larger than if verbatim encoding mode
+       were to be used. */
 
-    s->blocksize    = blocksize;
-    s->samplerate   = samplerate;
-    s->bps          = bps;
-    s->decorrelation= decorrelation;
+    int count;
 
-//    dump_headers(s);
-
-    /* subframes */
-    for (i = 0; i < s->channels; i++)
-    {
-//        av_log(s->avctx, AV_LOG_DEBUG, "decoded: %x residual: %x\n", s->decoded[i], s->residual[i]);
-        if (decode_subframe(s, i) < 0)
-            return -1;
+    count = 16;                  /* frame header */
+    count += ch * ((7+bps+7)/8); /* subframe headers */
+    if (ch == 2) {
+        /* for stereo, need to account for using decorrelation */
+        count += (( 2*bps+1) * blocksize + 7) / 8;
+    } else {
+        count += ( ch*bps    * blocksize + 7) / 8;
     }
+    count += 2; /* frame footer */
 
-    align_get_bits(&s->gb);
-
-    /* frame footer */
-    skip_bits(&s->gb, 16); /* data crc */
-
-    return 0;
+    return count;
 }
 
-static inline int16_t shift_to_16_bits(int32_t data, int bps)
+int avpriv_flac_is_extradata_valid(AVCodecContext *avctx,
+                               enum FLACExtradataFormat *format,
+                               uint8_t **streaminfo_start)
 {
-    if (bps == 24) {
-        return (data >> 8);
-    } else if (bps == 20) {
-        return (data >> 4);
+    if (!avctx->extradata || avctx->extradata_size < FLAC_STREAMINFO_SIZE) {
+        av_log(avctx, AV_LOG_ERROR, "extradata NULL or too small.\n");
+        return 0;
+    }
+    if (AV_RL32(avctx->extradata) != MKTAG('f','L','a','C')) {
+        /* extradata contains STREAMINFO only */
+        if (avctx->extradata_size != FLAC_STREAMINFO_SIZE) {
+            av_log(avctx, AV_LOG_WARNING, "extradata contains %d bytes too many.\n",
+                   FLAC_STREAMINFO_SIZE-avctx->extradata_size);
+        }
+        *format = FLAC_EXTRADATA_FORMAT_STREAMINFO;
+        *streaminfo_start = avctx->extradata;
     } else {
-        return data;
+        if (avctx->extradata_size < 8+FLAC_STREAMINFO_SIZE) {
+            av_log(avctx, AV_LOG_ERROR, "extradata too small.\n");
+            return 0;
+        }
+        *format = FLAC_EXTRADATA_FORMAT_FULL_HEADER;
+        *streaminfo_start = &avctx->extradata[8];
     }
+    return 1;
 }
 
-static int flac_decode_frame(AVCodecContext *avctx,
-                            void *data, int *data_size,
-                            uint8_t *buf, int buf_size)
+void ff_flac_set_channel_layout(AVCodecContext *avctx)
 {
-    FLACContext *s = avctx->priv_data;
-    int metadata_last, metadata_type, metadata_size;
-    int tmp = 0, i, j = 0, input_buf_size = 0;
-    int16_t *samples = data;
-
-    if(s->max_framesize == 0){
-        s->max_framesize= 65536; // should hopefully be enough for the first header
-        s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
-    }
-
-    if(1 && s->max_framesize){//FIXME truncated
-            buf_size= FFMAX(FFMIN(buf_size, s->max_framesize - s->bitstream_size), 0);
-            input_buf_size= buf_size;
-
-            if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
-//                printf("memmove\n");
-                memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
-                s->bitstream_index=0;
-            }
-            memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
-            buf= &s->bitstream[s->bitstream_index];
-            buf_size += s->bitstream_size;
-            s->bitstream_size= buf_size;
-
-            if(buf_size < s->max_framesize){
-//                printf("wanna more data ...\n");
-                return input_buf_size;
-            }
-    }
-
-    init_get_bits(&s->gb, buf, buf_size*8);
-
-    /* fLaC signature (be) */
-    if (show_bits_long(&s->gb, 32) == bswap_32(ff_get_fourcc("fLaC")))
-    {
-        skip_bits(&s->gb, 32);
-
-        av_log(s->avctx, AV_LOG_DEBUG, "STREAM HEADER\n");
-        do {
-            metadata_last = get_bits(&s->gb, 1);
-            metadata_type = get_bits(&s->gb, 7);
-            metadata_size = get_bits_long(&s->gb, 24);
-
-            av_log(s->avctx, AV_LOG_DEBUG, " metadata block: flag = %d, type = %d, size = %d\n",
-                metadata_last, metadata_type,
-                metadata_size);
-            if(metadata_size){
-                switch(metadata_type)
-                {
-                case METADATA_TYPE_STREAMINFO:{
-                    metadata_streaminfo(s);
-
-                    /* Buffer might have been reallocated, reinit bitreader */
-                    if(buf != &s->bitstream[s->bitstream_index])
-                    {
-                        int bits_count = get_bits_count(&s->gb);
-                        buf= &s->bitstream[s->bitstream_index];
-                        init_get_bits(&s->gb, buf, buf_size*8);
-                        skip_bits(&s->gb, bits_count);
-                    }
-
-                    dump_headers(s);
-                    break;}
-                default:
-                    for(i=0; i<metadata_size; i++)
-                        skip_bits(&s->gb, 8);
-                }
-            }
-        } while(!metadata_last);
-    }
+    if (avctx->channels <= FF_ARRAY_ELEMS(flac_channel_layouts))
+        avctx->channel_layout = flac_channel_layouts[avctx->channels - 1];
     else
-    {
-
-        tmp = show_bits(&s->gb, 16);
-        if(tmp != 0xFFF8){
-            av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n");
-            while(get_bits_count(&s->gb)/8+2 < buf_size && show_bits(&s->gb, 16) != 0xFFF8)
-                skip_bits(&s->gb, 8);
-            goto end; // we may not have enough bits left to decode a frame, so try next time
-        }
-        skip_bits(&s->gb, 16);
-        if (decode_frame(s) < 0){
-            av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
-            s->bitstream_size=0;
-            s->bitstream_index=0;
-            return -1;
-        }
-    }
-
+        avctx->channel_layout = 0;
+}
 
-#if 0
-    /* fix the channel order here */
-    if (s->order == MID_SIDE)
-    {
-        short *left = samples;
-        short *right = samples + s->blocksize;
-        for (i = 0; i < s->blocksize; i += 2)
-        {
-            uint32_t x = s->decoded[0][i];
-            uint32_t y = s->decoded[0][i+1];
+void avpriv_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
+                              const uint8_t *buffer)
+{
+    GetBitContext gb;
+    init_get_bits(&gb, buffer, FLAC_STREAMINFO_SIZE*8);
 
-            right[i] = x - (y / 2);
-            left[i] = right[i] + y;
-        }
-        *data_size = 2 * s->blocksize;
+    skip_bits(&gb, 16); /* skip min blocksize */
+    s->max_blocksize = get_bits(&gb, 16);
+    if (s->max_blocksize < FLAC_MIN_BLOCKSIZE) {
+        av_log(avctx, AV_LOG_WARNING, "invalid max blocksize: %d\n",
+               s->max_blocksize);
+        s->max_blocksize = 16;
     }
-    else
-    {
-    for (i = 0; i < s->channels; i++)
-    {
-        switch(s->order)
-        {
-            case INDEPENDENT:
-                for (j = 0; j < s->blocksize; j++)
-                    samples[(s->blocksize*i)+j] = s->decoded[i][j];
-                break;
-            case LEFT_SIDE:
-            case RIGHT_SIDE:
-                if (i == 0)
-                    for (j = 0; j < s->blocksize; j++)
-                        samples[(s->blocksize*i)+j] = s->decoded[0][j];
-                else
-                    for (j = 0; j < s->blocksize; j++)
-                        samples[(s->blocksize*i)+j] = s->decoded[0][j] - s->decoded[i][j];
-                break;
-//            case MID_SIDE:
-//                av_log(s->avctx, AV_LOG_DEBUG, "mid-side unsupported\n");
-        }
-        *data_size += s->blocksize;
-    }
-    }
-#else
-    switch(s->decorrelation)
-    {
-        case INDEPENDENT:
-            for (j = 0; j < s->blocksize; j++)
-            {
-                for (i = 0; i < s->channels; i++)
-                    *(samples++) = shift_to_16_bits(s->decoded[i][j], s->bps);
-            }
-            break;
-        case LEFT_SIDE:
-            assert(s->channels == 2);
-            for (i = 0; i < s->blocksize; i++)
-            {
-                *(samples++) = shift_to_16_bits(s->decoded[0][i], s->bps);
-                *(samples++) = shift_to_16_bits(s->decoded[0][i]
-                                              - s->decoded[1][i], s->bps);
-            }
-            break;
-        case RIGHT_SIDE:
-            assert(s->channels == 2);
-            for (i = 0; i < s->blocksize; i++)
-            {
-                *(samples++) = shift_to_16_bits(s->decoded[0][i]
-                                              + s->decoded[1][i], s->bps);
-                *(samples++) = shift_to_16_bits(s->decoded[1][i], s->bps);
-            }
-            break;
-        case MID_SIDE:
-            assert(s->channels == 2);
-            for (i = 0; i < s->blocksize; i++)
-            {
-                int mid, side;
-                mid = s->decoded[0][i];
-                side = s->decoded[1][i];
 
-#if 1 //needs to be checked but IMHO it should be binary identical
-                mid -= side>>1;
-                *(samples++) = shift_to_16_bits(mid + side, s->bps);
-                *(samples++) = shift_to_16_bits(mid, s->bps);
-#else
+    skip_bits(&gb, 24); /* skip min frame size */
+    s->max_framesize = get_bits_long(&gb, 24);
 
-                mid <<= 1;
-                if (side & 1)
-                    mid++;
-                *(samples++) = (mid + side) >> 1;
-                *(samples++) = (mid - side) >> 1;
-#endif
-            }
-            break;
-    }
-#endif
+    s->samplerate = get_bits_long(&gb, 20);
+    s->channels = get_bits(&gb, 3) + 1;
+    s->bps = get_bits(&gb, 5) + 1;
 
-    *data_size = (int8_t *)samples - (int8_t *)data;
-//    av_log(s->avctx, AV_LOG_DEBUG, "data size: %d\n", *data_size);
+    avctx->channels = s->channels;
+    avctx->sample_rate = s->samplerate;
+    avctx->bits_per_raw_sample = s->bps;
+    ff_flac_set_channel_layout(avctx);
 
-//    s->last_blocksize = s->blocksize;
-end:
-    i= (get_bits_count(&s->gb)+7)/8;;
-    if(i > buf_size){
-        av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
-        s->bitstream_size=0;
-        s->bitstream_index=0;
-        return -1;
-    }
+    s->samples  = get_bits_long(&gb, 32) << 4;
+    s->samples |= get_bits(&gb, 4);
 
-    if(s->bitstream_size){
-        s->bitstream_index += i;
-        s->bitstream_size  -= i;
-        return input_buf_size;
-    }else
-        return i;
+    skip_bits_long(&gb, 64); /* md5 sum */
+    skip_bits_long(&gb, 64); /* md5 sum */
 }
 
-static int flac_decode_close(AVCodecContext *avctx)
+void avpriv_flac_parse_block_header(const uint8_t *block_header,
+                                int *last, int *type, int *size)
 {
-    FLACContext *s = avctx->priv_data;
-    int i;
-
-    for (i = 0; i < s->channels; i++)
-    {
-        av_freep(&s->decoded[i]);
-    }
-    av_freep(&s->bitstream);
-
-    return 0;
+    int tmp = bytestream_get_byte(&block_header);
+    if (last)
+        *last = tmp & 0x80;
+    if (type)
+        *type = tmp & 0x7F;
+    if (size)
+        *size = bytestream_get_be24(&block_header);
 }
-
-static void flac_flush(AVCodecContext *avctx){
-    FLACContext *s = avctx->priv_data;
-
-    s->bitstream_size=
-    s->bitstream_index= 0;
-}
-
-AVCodec flac_decoder = {
-    "flac",
-    CODEC_TYPE_AUDIO,
-    CODEC_ID_FLAC,
-    sizeof(FLACContext),
-    flac_decode_init,
-    NULL,
-    flac_decode_close,
-    flac_decode_frame,
-    .flush= flac_flush,
-};