flac decoder by (Alex Beregszaszi <alex at fsn dot hu>)

Originally committed as revision 2790 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 651 insertions, 0 deletions

diff --git a/libavcodec/flac.c b/libavcodec/flac.c
new file mode 100644
index 0000000000..77854d5028
--- /dev/null
+++ b/libavcodec/flac.c
@@ -0,0 +1,651 @@
+/*
+ * FLAC (Free Lossless Audio Codec) decoder
+ * Copyright (c) 2003 Alex Beregszaszi
+ *
+ * This library 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.
+ *
+ * This library 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
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/**
+ * @file flac.c
+ * FLAC (Free Lossless Audio Codec) decoder
+ * @author Alex Beregszaszi
+ */
+ 
+#include "avcodec.h"
+#include "golomb.h"
+
+#define MAX_CHANNELS 8
+#define MAX_BLOCKSIZE 65535
+
+enum channel_order {
+    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 channel_order order;
+
+    uint8_t *residual[MAX_CHANNELS];
+    uint32_t *decoded[MAX_CHANNELS];
+} 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 uint64_t get_uvlc(GetBitContext *gb, int is64)
+{
+    uint64_t val = 0;
+    int i = 0;
+
+    while(i++ < 5+is64)
+    {
+        const int tmp = get_bits(gb, 8);
+        
+        if (tmp & 0x80)
+            val = (val << 7) + tmp - 0x80;
+        else
+            return (val << 7) + tmp;
+    }
+    return -1;
+}
+
+static int flac_decode_init(AVCodecContext * avctx)
+{
+    return 0;
+}
+
+static void dump_headers(FLACContext *s)
+{
+    printf("  Blocksize: %d .. %d (%d)\n", s->min_blocksize, s->max_blocksize, s->blocksize);
+    printf("  Framesize: %d .. %d\n", s->min_framesize, s->max_framesize);
+    printf("  Samplerate: %d\n", s->samplerate);
+    printf("  Channels: %d\n", s->channels);
+    printf("  Bits: %d\n", s->bps);
+}
+
+static void metadata_streaminfo(FLACContext *s)
+{
+    int i;
+
+    /* 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 */
+
+    for (i = 0; i < s->channels; i++)
+    {
+        s->decoded[i] = av_realloc(s->decoded[i], sizeof(uint32_t)*s->max_blocksize);
+        s->residual[i] = av_realloc(s->residual[i], sizeof(uint8_t)*s->max_blocksize);
+    }
+}
+
+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)
+        return -1;
+    
+    rice_order = get_bits(&s->gb, 4);
+
+    samples = (rice_order > 0) ?
+        (s->blocksize >> rice_order) : (s->blocksize - pred_order);
+
+    for (partition = 0; partition < (1 << rice_order); partition++)
+    {
+        tmp = get_bits(&s->gb, 4);
+        if (tmp == 0)
+        {
+            i = (!rice_order || partition) ? 0 : pred_order;
+            for (; i < samples; i++, sample++)
+                s->residual[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, 0, 0);
+            printf("zero k\n");
+        }
+        else if (tmp == 15)
+        {
+            printf("fixed len partition\n");
+            tmp = get_bits(&s->gb, 5);
+            i = (!rice_order || partition) ? 0 : pred_order;
+            for (; i < samples; i++, sample++)
+                s->residual[channel][sample] = get_bits(&s->gb, tmp);
+        }
+        else
+        {
+//            printf("rice coded partition\n");
+#if 1
+            i = (!rice_order || partition) ? 0 : pred_order;
+            for (; i < samples; i++, sample++)
+                s->residual[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, 0, 0);
+#else
+            i = ((!rice_order || partition) ? samples : samples - pred_order) + sample;
+            for (; sample < i; sample++)
+                s->residual[channel][sample] = get_ur_golomb(&s->gb, tmp, 0, 0);
+//                s->residual[channel][sample] = get_se_golomb(&s->gb);
+#endif
+        }
+    }
+
+    printf("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;
+        
+    printf("  SUBFRAME FIXED\n");
+        
+    /* warm up samples */
+    printf("   warm up samples: %d\n", pred_order);
+        
+    for (i = 0; i < pred_order; i++)
+    {
+        s->decoded[channel][i] = get_bits(&s->gb, s->curr_bps);
+        printf("    %d: %d\n", i, s->decoded[channel][i]);
+    }
+    
+    if (decode_residuals(s, channel, pred_order) < 0)
+        return -1;
+
+    switch(pred_order)
+    {
+        case 0:
+            for (i = pred_order; i < s->blocksize; i++)
+                s->decoded[channel][i] = s->residual[channel][i];
+            break;
+        case 1:
+            for (i = pred_order; i < s->blocksize; i++)
+                s->decoded[channel][i] = s->residual[channel][i] +
+                                        s->decoded[channel][i-1];
+            break;
+        case 2:
+            for (i = pred_order; i < s->blocksize; i++)
+                s->decoded[channel][i] = s->residual[channel][i] +
+                                        (s->decoded[channel][i-1] << 1) -
+                                        s->decoded[channel][i-2];
+            break;
+        case 3:
+            for (i = pred_order; i < s->blocksize; i++)
+                s->decoded[channel][i] = s->residual[channel][i] +
+                                        (((s->decoded[channel][i-1] -
+                                        s->decoded[channel][i-2]) << 1) +
+                                        (s->decoded[channel][i-1] -
+                                        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] = s->residual[channel][i] +
+                                        ((s->decoded[channel][i-1] +
+                                        s->decoded[channel][i-3]) << 2) -
+                                        ((s->decoded[channel][i-2] << 2) +
+                                        (s->decoded[channel][i-2] << 1)) -
+                                        s->decoded[channel][i-4];
+            break;
+    }
+    
+    return 0;
+}
+
+static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order)
+{
+    int sum, i, j;
+    int coeff_prec, qlevel;
+    int coeffs[pred_order];
+        
+    printf("  SUBFRAME LPC\n");
+        
+    /* warm up samples */
+    printf("   warm up samples: %d\n", pred_order);
+        
+    for (i = 0; i < pred_order; i++)
+    {
+        s->decoded[channel][i] = get_bits(&s->gb, s->curr_bps);
+        printf("    %d: %d\n", i, s->decoded[channel][i]);
+    }
+    
+    coeff_prec = get_bits(&s->gb, 4) + 1;
+    if (coeff_prec == 16)
+    {
+        printf("invalid coeff precision\n");
+        return -1;
+    }
+    printf("   qlp coeff prec: %d\n", coeff_prec);
+    qlevel = get_bits(&s->gb, 5);
+    printf("   quant level: %d\n", qlevel);
+    
+    for (i = 0; i < pred_order; i++)
+    {
+        coeffs[i] = get_bits(&s->gb, coeff_prec);
+        printf("    %d: %d\n", i, coeffs[i]);
+    }
+    
+    if (decode_residuals(s, channel, pred_order) < 0)
+        return -1;
+
+    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] = s->residual[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 (get_bits1(&s->gb))
+    {
+        printf("invalid subframe padding\n");
+        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 (get_bits1(&s->gb))
+    {
+        wasted = 1;
+        while (!get_bits1(&s->gb))
+            wasted++;
+        s->curr_bps -= wasted;
+    }
+
+    if (type == 0)
+    {
+        printf("coding type: constant\n");
+        tmp = get_bits(&s->gb, s->curr_bps);
+        for (i = 0; i < s->blocksize; i++)
+            s->decoded[channel][i] = tmp;
+    }
+    else if (type == 1)
+    {
+        printf("coding type: verbatim\n");
+        for (i = 0; i < s->blocksize; i++)
+            s->decoded[channel][i] = get_bits(&s->gb, s->curr_bps);
+    }
+    else if ((type >= 8) && (type <= 12))
+    {
+        printf("coding type: fixed\n");
+        if (decode_subframe_fixed(s, channel, type & ~0x8) < 0)
+            return -1;
+    }
+    else if (type >= 32)
+    {
+        printf("coding type: lpc\n");
+        if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0)
+            return -1;
+    }
+    else
+    {
+        printf("invalid coding type\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 blocksize_code, sample_rate_code, sample_size_code, assignment, i;
+    
+    blocksize_code = get_bits(&s->gb, 4);
+    if (blocksize_code == 0)
+        s->blocksize = s->min_blocksize;
+    else if (blocksize_code == 1)
+        s->blocksize = 192;
+    else if (blocksize_code <= 5)
+        s->blocksize = 576 << (blocksize_code - 2);
+    else if (blocksize_code >= 8)
+        s->blocksize = 256 << (blocksize_code - 8);
+
+    sample_rate_code = get_bits(&s->gb, 4);
+    if ((sample_rate_code > 3) && (sample_rate_code < 12))
+        s->samplerate = sample_rate_table[sample_rate_code];
+    
+    assignment = get_bits(&s->gb, 4); /* channel assignment */
+    if (assignment < 8)
+    {
+        s->order = INDEPENDENT;
+        if (s->channels != assignment+1)
+            printf("channel number and number of assigned channels differ!\n");
+        printf("channels: %d\n", assignment+1);
+    }
+    else if (assignment == 8)
+    {
+        s->order = LEFT_SIDE;
+        printf("left/side\n");
+    }
+    else if (assignment == 9)
+    {
+        s->order = RIGHT_SIDE;
+        printf("right/side\n");
+    }
+    else if (assignment == 10)
+    {
+        s->order = MID_SIDE;
+        printf("mid/side\n");
+    }
+    else
+    {
+        printf("unsupported channel assignment\n");
+        return -1;
+    }
+
+    if ((assignment >= 8) && (s->channels != 2))
+    {
+        return -1;
+    }
+        
+    sample_size_code = get_bits(&s->gb, 3);
+    if (s->bps != 0)
+        s->bps = sample_size_table[sample_size_code];
+
+    if ((sample_size_code == 3) || (sample_size_code == 7))
+    {
+        printf("invalid sample size code (%d)\n", sample_size_code);
+        return -1;
+    }
+
+    if (get_bits1(&s->gb))
+    {
+        printf("broken stream, invalid padding\n");
+//        return -1;
+    }
+    
+    if (((blocksize_code == 6) || (blocksize_code == 7)) &&
+        (s->min_blocksize != s->max_blocksize))
+    {
+        get_uvlc(&s->gb, 1);
+    }
+    else
+        get_uvlc(&s->gb, 0);
+    
+    if (blocksize_code == 6)
+        s->blocksize = get_bits(&s->gb, 8)+1;
+    if (blocksize_code == 7)
+        s->blocksize = get_bits(&s->gb, 16)+1;
+
+    if ((sample_rate_code > 11) && (sample_rate_code < 15))
+    {
+        switch(sample_rate_code)
+        {
+            case 12:
+                s->samplerate = get_bits(&s->gb, 8) * 1000;
+                break;
+            case 13:
+                s->samplerate = get_bits(&s->gb, 16);
+                break;
+            case 14:
+                s->samplerate = get_bits(&s->gb, 16) * 10;
+                break;
+        }
+    }
+
+    skip_bits(&s->gb, 8); /* header crc */
+
+    dump_headers(s);
+
+    /* subframes */
+    for (i = 0; i < s->channels; i++)
+    {
+        if (s->blocksize != s->last_blocksize)
+        {
+            s->decoded[i] = av_realloc(s->decoded[i], sizeof(uint32_t)*s->blocksize);
+            s->residual[i] = av_realloc(s->residual[i], sizeof(uint8_t)*s->blocksize);
+        }
+        printf("decoded: %x residual: %x\n", s->decoded[i], s->residual[i]);
+        if (decode_subframe(s, i) < 0)
+            return -1;
+    }
+    
+    align_get_bits(&s->gb);
+
+    /* frame footer */
+    skip_bits(&s->gb, 16); /* data crc */
+
+    return 0;
+}
+
+static int flac_decode_frame(AVCodecContext *avctx,
+                            void *data, int *data_size,
+                            uint8_t *buf, int buf_size)
+{
+    FLACContext *s = avctx->priv_data;
+    int metadata_flag, metadata_type, metadata_size;
+    int tmp = 0, i, j = 0;
+    int16_t *samples = data, *left, *right;
+
+    *data_size = 0;
+
+    s->avctx = avctx;
+
+    init_get_bits(&s->gb, buf, buf_size*8);
+    
+    /* fLaC signature (be) */
+    if (get_bits_long(&s->gb, 32) == bswap_32(ff_get_fourcc("fLaC")))
+    {
+        printf("STREAM HEADER\n");
+        do {
+            metadata_flag = get_bits(&s->gb, 1);
+            metadata_type = get_bits(&s->gb, 7);
+            metadata_size = get_bits_long(&s->gb, 24);
+            
+            printf(" metadata block: flag = %d, type = %d, size = %d\n",
+                metadata_flag, metadata_type,
+                metadata_size);
+
+            switch(metadata_type)
+            {
+                case METADATA_TYPE_STREAMINFO:
+                    metadata_streaminfo(s);
+                    dump_headers(s);
+                    break;
+                default:
+                    while ((metadata_size -= 8) > 0)
+                        skip_bits(&s->gb, 8);
+            }
+        } while(metadata_flag != 1);
+    }
+    else
+    {
+        init_get_bits(&s->gb, buf, buf_size*8);
+        tmp = get_bits(&s->gb, 16);
+        if (tmp == 0xfff8)
+            printf("FRAME HEADER\n");
+
+        if (decode_frame(s) < 0)
+            return -1;
+    }
+    
+#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];
+
+            right[i] = x - (y / 2);
+            left[i] = right[i] + y;
+        }
+        *data_size = 2 * s->blocksize;
+    }
+    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:
+//                printf("mid-side unsupported\n");
+        }
+        *data_size += s->blocksize;
+    }
+    }
+#else
+    switch(s->order)
+    {
+        case INDEPENDENT:
+            for (i = 0; i < s->channels; i++)
+            {
+                for (j = 0; j < s->blocksize; j++)
+                    *(samples++) = s->decoded[i][j];
+                *data_size += s->blocksize;
+            }
+            break;
+        case LEFT_SIDE:
+            assert(s->channels == 2);
+            for (i = 0; i < s->blocksize; i++)
+            {
+                *(samples++) = s->decoded[0][i];
+                *(samples++) = s->decoded[0][i] - s->decoded[1][i];
+            }
+            *data_size = 2*s->blocksize;
+            break;
+        case RIGHT_SIDE:
+            assert(s->channels == 2);
+            for (i = 0; i < s->blocksize; i++)
+            {
+                *(samples++) = s->decoded[0][i] + s->decoded[1][i];
+                *(samples++) = s->decoded[1][i];
+            }
+            *data_size = 2*s->blocksize;
+            break;
+        case MID_SIDE:
+            assert(s->channels == 2);
+            for (i = 0; i < s->blocksize; i++)
+            {
+                int16_t mid, side;
+                mid = s->decoded[0][i];
+                side = s->decoded[1][i];
+                
+                mid <<= 1;
+                if (side & 1)
+                    mid++;
+                *(samples++) = (mid + side) >> 1;
+                *(samples++) = (mid - side) >> 1;
+            }
+            *data_size = 2*s->blocksize;
+            break;
+    }
+#endif
+
+//    *data_size = (int8_t *)samples - (int8_t *)data;
+    printf("data size: %d\n", *data_size);
+
+    s->last_blocksize = s->blocksize;
+
+    return (get_bits_count(&s->gb)+7)/8;
+}
+
+static int flac_decode_close(AVCodecContext *avctx)
+{
+    FLACContext *s = avctx->priv_data;
+    int i;
+    
+    for (i = 0; i < s->channels; i++)
+    {
+        if (s->decoded[i])
+            av_free(s->decoded[i]);
+        if (s->residual[i])
+            av_free(s->residual[i]);
+    }
+    
+    return 0;
+}
+
+AVCodec flac_decoder = {
+    "flac",
+    CODEC_TYPE_AUDIO,
+    CODEC_ID_FLAC,
+    sizeof(FLACContext),
+    flac_decode_init,
+    NULL,
+    flac_decode_close,
+    flac_decode_frame,
+};