Beispiel #1
0
static av_cold int cook_decode_close(AVCodecContext *avctx)
{
    int i;
    COOKContext *q = avctx->priv_data;
    av_log(avctx,AV_LOG_DEBUG, "Deallocating memory.\n");

    /* Free allocated memory buffers. */
    av_free(q->mlt_window);
    av_free(q->decoded_bytes_buffer);

    /* Free the transform. */
    ff_mdct_end(&q->mdct_ctx);

    /* Free the VLC tables. */
    for (i=0 ; i<13 ; i++) {
        free_vlc(&q->envelope_quant_index[i]);
    }
    for (i=0 ; i<7 ; i++) {
        free_vlc(&q->sqvh[i]);
    }
    for (i=0 ; i<q->num_subpackets ; i++) {
        free_vlc(&q->subpacket[i].ccpl);
    }

    av_log(avctx,AV_LOG_DEBUG,"Memory deallocated.\n");

    return 0;
}
Beispiel #2
0
static int cook_decode_close(AVCodecContext *avctx)
{
    int i;
    COOKContext *q = avctx->priv_data;
    av_log(avctx,AV_LOG_DEBUG, "Deallocating memory.\n");

    /* Free allocated memory buffers. */
    av_free(q->mlt_window);
    av_free(q->decoded_bytes_buffer);

    /* Free the transform. */
    ff_mdct_end(&q->mdct_ctx);

    /* Free the VLC tables. */
    for (i=0 ; i<13 ; i++) {
        free_vlc(&q->envelope_quant_index[i]);
    }
    for (i=0 ; i<7 ; i++) {
        free_vlc(&q->sqvh[i]);
    }
    if(q->nb_channels==2 && q->joint_stereo==1 ){
        free_vlc(&q->ccpl);
    }

    av_log(NULL,AV_LOG_DEBUG,"Memory deallocated.\n");

    return 0;
}
static int read_old_huffman_tables(HYuvContext *s){
#if 1
    GetBitContext gb;
    int i;

    init_get_bits(&gb, classic_shift_luma, sizeof(classic_shift_luma)*8);
    if(read_len_table(s->len[0], &gb)<0)
        return -1;
    init_get_bits(&gb, classic_shift_chroma, sizeof(classic_shift_chroma)*8);
    if(read_len_table(s->len[1], &gb)<0)
        return -1;

    for(i=0; i<256; i++) s->bits[0][i] = classic_add_luma  [i];
    for(i=0; i<256; i++) s->bits[1][i] = classic_add_chroma[i];

    if(s->bitstream_bpp >= 24){
        memcpy(s->bits[1], s->bits[0], 256*sizeof(uint32_t));
        memcpy(s->len[1] , s->len [0], 256*sizeof(uint8_t));
    }
    memcpy(s->bits[2], s->bits[1], 256*sizeof(uint32_t));
    memcpy(s->len[2] , s->len [1], 256*sizeof(uint8_t));

    for(i=0; i<3; i++){
        free_vlc(&s->vlc[i]);
        init_vlc(&s->vlc[i], VLC_BITS, 256, s->len[i], 1, 1, s->bits[i], 4, 4, 0);
    }

    generate_joint_tables(s);

    return 0;
#else
    av_log(s->avctx, AV_LOG_DEBUG, "v1 huffyuv is not supported \n");
    return -1;
#endif
}
Beispiel #4
0
static void tm2_free_codes(TM2Codes *code)
{
    if(code->recode)
        av_free(code->recode);
    if(code->vlc.table)
        free_vlc(&code->vlc);
}
Beispiel #5
0
static int read_huffman_tables(HYuvContext *s, uint8_t *src, int length){
    GetBitContext gb;
    int i;

    init_get_bits(&gb, src, length*8);

    for(i=0; i<3; i++){
        if(read_len_table(s->len[i], &gb)<0)
            return -1;
        if(generate_bits_table(s->bits[i], s->len[i])<0){
            return -1;
        }
#if 0
for(j=0; j<256; j++){
printf("%6X, %2d,  %3d\n", s->bits[i][j], s->len[i][j], j);
}
#endif
        free_vlc(&s->vlc[i]);
        init_vlc(&s->vlc[i], VLC_BITS, 256, s->len[i], 1, 1, s->bits[i], 4, 4, 0);
    }

    generate_joint_tables(s);

    return (get_bits_count(&gb)+7)/8;
}
static int mp_decode_frame(AVCodecContext *avctx,
                           void *data, int *data_size,
                           AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    MotionPixelsContext *mp = avctx->priv_data;
    GetBitContext gb;
    int i, count1, count2, sz;

    mp->frame.reference = 1;
    mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
    if (avctx->reget_buffer(avctx, &mp->frame)) {
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    /* le32 bitstream msb first */
    av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!mp->bswapbuf)
        return AVERROR(ENOMEM);
    mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
    if (buf_size & 3)
        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);

    memset(mp->changes_map, 0, avctx->width * avctx->height);
    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
        count1 = get_bits(&gb, 12);
        count2 = get_bits(&gb, 12);
        mp_read_changes_map(mp, &gb, count1, 8, i);
        mp_read_changes_map(mp, &gb, count2, 4, i);
    }

    mp->codes_count = get_bits(&gb, 4);
    if (mp->codes_count == 0)
        goto end;

    if (mp->changes_map[0] == 0) {
        *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
        mp->changes_map[0] = 1;
    }
    mp_read_codes_table(mp, &gb);

    sz = get_bits(&gb, 18);
    if (avctx->extradata[0] != 5)
        sz += get_bits(&gb, 18);
    if (sz == 0)
        goto end;

    init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0);
    mp_decode_frame_helper(mp, &gb);
    free_vlc(&mp->vlc);

end:
    *data_size = sizeof(AVFrame);
    *(AVFrame *)data = mp->frame;
    return buf_size;
}
static int read_huffman_tables(HYuvContext *s, const uint8_t *src, int length){
    GetBitContext gb;
    int i;

    init_get_bits(&gb, src, length*8);

    for(i=0; i<3; i++){
        if(read_len_table(s->len[i], &gb)<0)
            return -1;
        if(generate_bits_table(s->bits[i], s->len[i])<0){
            return -1;
        }
        free_vlc(&s->vlc[i]);
        init_vlc(&s->vlc[i], VLC_BITS, 256, s->len[i], 1, 1, s->bits[i], 4, 4, 0);
    }

    generate_joint_tables(s);

    return (get_bits_count(&gb)+7)/8;
}
Beispiel #8
0
/**
 * Decode Smacker audio data
 */
static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
{
    GetBitContext gb;
    HuffContext h[4];
    VLC vlc[4];
    int16_t *samples = data;
    int val;
    int i, res;
    int unp_size;
    int bits, stereo;
    int pred[2] = {0, 0};

    unp_size = AV_RL32(buf);

    init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

    if(!get_bits1(&gb)){
        av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
        *data_size = 0;
        return 1;
    }
    stereo = get_bits1(&gb);
    bits = get_bits1(&gb);
    if (unp_size & 0xC0000000 || (unp_size << !bits) > *data_size) {
        av_log(avctx, AV_LOG_ERROR, "Frame is too large to fit in buffer\n");
        return -1;
    }

    memset(vlc, 0, sizeof(VLC) * 4);
    memset(h, 0, sizeof(HuffContext) * 4);
    // Initialize
    for(i = 0; i < (1 << (bits + stereo)); i++) {
        h[i].length = 256;
        h[i].maxlength = 0;
        h[i].current = 0;
        h[i].bits = av_mallocz(256 * 4);
        h[i].lengths = av_mallocz(256 * sizeof(int));
        h[i].values = av_mallocz(256 * sizeof(int));
        skip_bits1(&gb);
        smacker_decode_tree(&gb, &h[i], 0, 0);
        skip_bits1(&gb);
        if(h[i].current > 1) {
            res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
                    h[i].lengths, sizeof(int), sizeof(int),
                    h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
            if(res < 0) {
                av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
                return -1;
            }
        }
    }
    if(bits) { //decode 16-bit data
        for(i = stereo; i >= 0; i--)
            pred[i] = bswap_16(get_bits(&gb, 16));
        for(i = 0; i < stereo; i++)
            *samples++ = pred[i];
        for(i = 0; i < unp_size / 2; i++) {
            if(i & stereo) {
                if(vlc[2].table)
                    res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[2].values[res];
                if(vlc[3].table)
                    res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[3].values[res] << 8;
                pred[1] += (int16_t)val;
                *samples++ = pred[1];
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[0].values[res];
                if(vlc[1].table)
                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[1].values[res] << 8;
                pred[0] += val;
                *samples++ = pred[0];
            }
        }
    } else { //8-bit data
        for(i = stereo; i >= 0; i--)
            pred[i] = get_bits(&gb, 8);
        for(i = 0; i < stereo; i++)
            *samples++ = (pred[i] - 0x80) << 8;
        for(i = 0; i < unp_size; i++) {
            if(i & stereo){
                if(vlc[1].table)
                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[1] += (int8_t)h[1].values[res];
                *samples++ = (pred[1] - 0x80) << 8;
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[0] += (int8_t)h[0].values[res];
                *samples++ = (pred[0] - 0x80) << 8;
            }
        }
        unp_size *= 2;
    }

    for(i = 0; i < 4; i++) {
        if(vlc[i].table)
            free_vlc(&vlc[i]);
        if(h[i].bits)
            av_free(h[i].bits);
        if(h[i].lengths)
            av_free(h[i].lengths);
        if(h[i].values)
            av_free(h[i].values);
    }

    *data_size = unp_size;
    return buf_size;
}
Beispiel #9
0
/**
 * Store large tree as FFmpeg's vlc codes
 */
static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int **recodes, int *last, int size)
{
    int res;
    HuffContext huff;
    HuffContext tmp1, tmp2;
    VLC vlc[2];
    int escapes[3];
    DBCtx ctx;

    if(size >= UINT_MAX>>4){ // (((size + 3) >> 2) + 3) << 2 must not overflow
        av_log(smk->avctx, AV_LOG_ERROR, "size too large\n");
        return -1;
    }

    tmp1.length = 256;
    tmp1.maxlength = 0;
    tmp1.current = 0;
    tmp1.bits = av_mallocz(256 * 4);
    tmp1.lengths = av_mallocz(256 * sizeof(int));
    tmp1.values = av_mallocz(256 * sizeof(int));

    tmp2.length = 256;
    tmp2.maxlength = 0;
    tmp2.current = 0;
    tmp2.bits = av_mallocz(256 * 4);
    tmp2.lengths = av_mallocz(256 * sizeof(int));
    tmp2.values = av_mallocz(256 * sizeof(int));

    memset(&vlc[0], 0, sizeof(VLC));
    memset(&vlc[1], 0, sizeof(VLC));

    if(get_bits1(gb)) {
        smacker_decode_tree(gb, &tmp1, 0, 0);
        skip_bits1(gb);
        res = init_vlc(&vlc[0], SMKTREE_BITS, tmp1.length,
                    tmp1.lengths, sizeof(int), sizeof(int),
                    tmp1.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
        if(res < 0) {
            av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
            return -1;
        }
    } else {
        av_log(smk->avctx, AV_LOG_ERROR, "Skipping low bytes tree\n");
    }
    if(get_bits1(gb)){
        smacker_decode_tree(gb, &tmp2, 0, 0);
        skip_bits1(gb);
        res = init_vlc(&vlc[1], SMKTREE_BITS, tmp2.length,
                    tmp2.lengths, sizeof(int), sizeof(int),
                    tmp2.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
        if(res < 0) {
            av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
            return -1;
        }
    } else {
        av_log(smk->avctx, AV_LOG_ERROR, "Skipping high bytes tree\n");
    }

    escapes[0]  = get_bits(gb, 8);
    escapes[0] |= get_bits(gb, 8) << 8;
    escapes[1]  = get_bits(gb, 8);
    escapes[1] |= get_bits(gb, 8) << 8;
    escapes[2]  = get_bits(gb, 8);
    escapes[2] |= get_bits(gb, 8) << 8;

    last[0] = last[1] = last[2] = -1;

    ctx.escapes[0] = escapes[0];
    ctx.escapes[1] = escapes[1];
    ctx.escapes[2] = escapes[2];
    ctx.v1 = &vlc[0];
    ctx.v2 = &vlc[1];
    ctx.recode1 = tmp1.values;
    ctx.recode2 = tmp2.values;
    ctx.last = last;

    huff.length = ((size + 3) >> 2) + 3;
    huff.maxlength = 0;
    huff.current = 0;
    huff.values = av_mallocz(huff.length * sizeof(int));

    smacker_decode_bigtree(gb, &huff, &ctx);
    skip_bits1(gb);
    if(ctx.last[0] == -1) ctx.last[0] = huff.current++;
    if(ctx.last[1] == -1) ctx.last[1] = huff.current++;
    if(ctx.last[2] == -1) ctx.last[2] = huff.current++;

    *recodes = huff.values;

    if(vlc[0].table)
        free_vlc(&vlc[0]);
    if(vlc[1].table)
        free_vlc(&vlc[1]);
    av_free(tmp1.bits);
    av_free(tmp1.lengths);
    av_free(tmp1.values);
    av_free(tmp2.bits);
    av_free(tmp2.lengths);
    av_free(tmp2.values);

    return 0;
}
Beispiel #10
0
static av_cold int dvvideo_init(AVCodecContext *avctx)
{
    DVVideoContext *s = avctx->priv_data;
    DSPContext dsp;
    static int done=0;
    int i, j;

    if (!done) {
        VLC dv_vlc;
        uint16_t new_dv_vlc_bits[NB_DV_VLC*2];
        uint8_t new_dv_vlc_len[NB_DV_VLC*2];
        uint8_t new_dv_vlc_run[NB_DV_VLC*2];
        int16_t new_dv_vlc_level[NB_DV_VLC*2];

        done = 1;

        /* dv_anchor lets each thread know its Id */
        for (i=0; i<DV_ANCHOR_SIZE; i++)
            dv_anchor[i] = (void*)(size_t)i;

        /* it's faster to include sign bit in a generic VLC parsing scheme */
        for (i=0, j=0; i<NB_DV_VLC; i++, j++) {
            new_dv_vlc_bits[j] = dv_vlc_bits[i];
            new_dv_vlc_len[j] = dv_vlc_len[i];
            new_dv_vlc_run[j] = dv_vlc_run[i];
            new_dv_vlc_level[j] = dv_vlc_level[i];

            if (dv_vlc_level[i]) {
                new_dv_vlc_bits[j] <<= 1;
                new_dv_vlc_len[j]++;

                j++;
                new_dv_vlc_bits[j] = (dv_vlc_bits[i] << 1) | 1;
                new_dv_vlc_len[j] = dv_vlc_len[i] + 1;
                new_dv_vlc_run[j] = dv_vlc_run[i];
                new_dv_vlc_level[j] = -dv_vlc_level[i];
            }
        }

        /* NOTE: as a trick, we use the fact the no codes are unused
           to accelerate the parsing of partial codes */
        init_vlc(&dv_vlc, TEX_VLC_BITS, j,
                 new_dv_vlc_len, 1, 1, new_dv_vlc_bits, 2, 2, 0);
        assert(dv_vlc.table_size == 1184);

        for(i = 0; i < dv_vlc.table_size; i++){
            int code= dv_vlc.table[i][0];
            int len = dv_vlc.table[i][1];
            int level, run;

            if(len<0){ //more bits needed
                run= 0;
                level= code;
            } else {
                run=   new_dv_vlc_run[code] + 1;
                level= new_dv_vlc_level[code];
            }
            dv_rl_vlc[i].len = len;
            dv_rl_vlc[i].level = level;
            dv_rl_vlc[i].run = run;
        }
        free_vlc(&dv_vlc);

        for (i = 0; i < NB_DV_VLC - 1; i++) {
           if (dv_vlc_run[i] >= DV_VLC_MAP_RUN_SIZE)
               continue;
#ifdef DV_CODEC_TINY_TARGET
           if (dv_vlc_level[i] >= DV_VLC_MAP_LEV_SIZE)
               continue;
#endif

           if (dv_vlc_map[dv_vlc_run[i]][dv_vlc_level[i]].size != 0)
               continue;

           dv_vlc_map[dv_vlc_run[i]][dv_vlc_level[i]].vlc = dv_vlc_bits[i] <<
                                                            (!!dv_vlc_level[i]);
           dv_vlc_map[dv_vlc_run[i]][dv_vlc_level[i]].size = dv_vlc_len[i] +
                                                             (!!dv_vlc_level[i]);
        }
        for (i = 0; i < DV_VLC_MAP_RUN_SIZE; i++) {
#ifdef DV_CODEC_TINY_TARGET
           for (j = 1; j < DV_VLC_MAP_LEV_SIZE; j++) {
              if (dv_vlc_map[i][j].size == 0) {
                  dv_vlc_map[i][j].vlc = dv_vlc_map[0][j].vlc |
                            (dv_vlc_map[i-1][0].vlc << (dv_vlc_map[0][j].size));
                  dv_vlc_map[i][j].size = dv_vlc_map[i-1][0].size +
                                          dv_vlc_map[0][j].size;
              }
           }
#else
           for (j = 1; j < DV_VLC_MAP_LEV_SIZE/2; j++) {
              if (dv_vlc_map[i][j].size == 0) {
                  dv_vlc_map[i][j].vlc = dv_vlc_map[0][j].vlc |
                            (dv_vlc_map[i-1][0].vlc << (dv_vlc_map[0][j].size));
                  dv_vlc_map[i][j].size = dv_vlc_map[i-1][0].size +
                                          dv_vlc_map[0][j].size;
              }
              dv_vlc_map[i][((uint16_t)(-j))&0x1ff].vlc =
                                            dv_vlc_map[i][j].vlc | 1;
              dv_vlc_map[i][((uint16_t)(-j))&0x1ff].size =
                                            dv_vlc_map[i][j].size;
           }
#endif
        }
    }

    /* Generic DSP setup */
    dsputil_init(&dsp, avctx);
    s->get_pixels = dsp.get_pixels;

    /* 88DCT setup */
    s->fdct[0] = dsp.fdct;
    s->idct_put[0] = dsp.idct_put;
    for (i=0; i<64; i++)
       s->dv_zigzag[0][i] = dsp.idct_permutation[ff_zigzag_direct[i]];

    /* 248DCT setup */
    s->fdct[1] = dsp.fdct248;
    s->idct_put[1] = ff_simple_idct248_put;  // FIXME: need to add it to DSP
    if(avctx->lowres){
        for (i=0; i<64; i++){
            int j= ff_zigzag248_direct[i];
            s->dv_zigzag[1][i] = dsp.idct_permutation[(j&7) + (j&8)*4 + (j&48)/2];
        }
    }else
        memcpy(s->dv_zigzag[1], ff_zigzag248_direct, 64);

    /* XXX: do it only for constant case */
    dv_build_unquantize_tables(s, dsp.idct_permutation);

    avctx->coded_frame = &s->picture;
    s->avctx= avctx;

    return 0;
}
static void generate_joint_tables(HYuvContext *s){
    uint16_t symbols[1<<VLC_BITS];
    uint16_t bits[1<<VLC_BITS];
    uint8_t len[1<<VLC_BITS];
    if(s->bitstream_bpp < 24){
        int p, i, y, u;
        for(p=0; p<3; p++){
            for(i=y=0; y<256; y++){
                int len0 = s->len[0][y];
                int limit = VLC_BITS - len0;
                if(limit <= 0 || !len0)
                    continue;
                for(u=0; u<256; u++){
                    int len1 = s->len[p][u];
                    if (len1 > limit || !len1)
                        continue;
                    av_assert0(i < (1 << VLC_BITS));
                    len[i] = len0 + len1;
                    bits[i] = (s->bits[0][y] << len1) + s->bits[p][u];
                    symbols[i] = (y<<8) + u;
                    if(symbols[i] != 0xffff) // reserved to mean "invalid"
                        i++;
                }
            }
            free_vlc(&s->vlc[3+p]);
            init_vlc_sparse(&s->vlc[3+p], VLC_BITS, i, len, 1, 1, bits, 2, 2, symbols, 2, 2, 0);
        }
    }else{
        uint8_t (*map)[4] = (uint8_t(*)[4])s->pix_bgr_map;
        int i, b, g, r, code;
        int p0 = s->decorrelate;
        int p1 = !s->decorrelate;
        // restrict the range to +/-16 becaues that's pretty much guaranteed to
        // cover all the combinations that fit in 11 bits total, and it doesn't
        // matter if we miss a few rare codes.
        for(i=0, g=-16; g<16; g++){
            int len0 = s->len[p0][g&255];
            int limit0 = VLC_BITS - len0;
            if (limit0 < 2 || !len0)
                continue;
            for(b=-16; b<16; b++){
                int len1 = s->len[p1][b&255];
                int limit1 = limit0 - len1;
                if (limit1 < 1 || !len1)
                    continue;
                code = (s->bits[p0][g&255] << len1) + s->bits[p1][b&255];
                for(r=-16; r<16; r++){
                    int len2 = s->len[2][r&255];
                    if (len2 > limit1 || !len2)
                        continue;
                    av_assert0(i < (1 << VLC_BITS));
                    len[i] = len0 + len1 + len2;
                    bits[i] = (code << len2) + s->bits[2][r&255];
                    if(s->decorrelate){
                        map[i][G] = g;
                        map[i][B] = g+b;
                        map[i][R] = g+r;
                    }else{
                        map[i][B] = g;
                        map[i][G] = b;
                        map[i][R] = r;
                    }
                    i++;
                }
            }
        }
        free_vlc(&s->vlc[3]);
        init_vlc(&s->vlc[3], VLC_BITS, i, len, 1, 1, bits, 2, 2, 0);
    }
}
Beispiel #12
0
/**
 * Decode Smacker audio data
 */
static int smka_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    SmackerAudioContext *s = avctx->priv_data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    GetBitContext gb;
    HuffContext h[4];
    VLC vlc[4];
    int16_t *samples;
    uint8_t *samples8;
    int val;
    int i, res, ret;
    int unp_size;
    int bits, stereo;
    int pred[2] = {0, 0};

    if (buf_size <= 4) {
        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
        return AVERROR(EINVAL);
    }

    unp_size = AV_RL32(buf);

    init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

    if(!get_bits1(&gb)){
        av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
        *got_frame_ptr = 0;
        return 1;
    }
    stereo = get_bits1(&gb);
    bits = get_bits1(&gb);
    if (stereo ^ (avctx->channels != 1)) {
        av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");
        return AVERROR(EINVAL);
    }
    if (bits && avctx->sample_fmt == AV_SAMPLE_FMT_U8) {
        av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");
        return AVERROR(EINVAL);
    }

    /* get output buffer */
    s->frame.nb_samples = unp_size / (avctx->channels * (bits + 1));
    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }
    samples  = (int16_t *)s->frame.data[0];
    samples8 =            s->frame.data[0];

    memset(vlc, 0, sizeof(VLC) * 4);
    memset(h, 0, sizeof(HuffContext) * 4);
    // Initialize
    for(i = 0; i < (1 << (bits + stereo)); i++) {
        h[i].length = 256;
        h[i].maxlength = 0;
        h[i].current = 0;
        h[i].bits = av_mallocz(256 * 4);
        h[i].lengths = av_mallocz(256 * sizeof(int));
        h[i].values = av_mallocz(256 * sizeof(int));
        skip_bits1(&gb);
        smacker_decode_tree(&gb, &h[i], 0, 0);
        skip_bits1(&gb);
        if(h[i].current > 1) {
            res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
                    h[i].lengths, sizeof(int), sizeof(int),
                    h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
            if(res < 0) {
                av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
                return -1;
            }
        }
    }
    if(bits) { //decode 16-bit data
        for(i = stereo; i >= 0; i--)
            pred[i] = sign_extend(av_bswap16(get_bits(&gb, 16)), 16);
        for(i = 0; i <= stereo; i++)
            *samples++ = pred[i];
        for(; i < unp_size / 2; i++) {
            if(get_bits_left(&gb)<0)
                return -1;
            if(i & stereo) {
                if(vlc[2].table)
                    res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[2].values[res];
                if(vlc[3].table)
                    res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[3].values[res] << 8;
                pred[1] += sign_extend(val, 16);
                *samples++ = av_clip_int16(pred[1]);
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[0].values[res];
                if(vlc[1].table)
                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[1].values[res] << 8;
                pred[0] += sign_extend(val, 16);
                *samples++ = av_clip_int16(pred[0]);
            }
        }
    } else { //8-bit data
        for(i = stereo; i >= 0; i--)
            pred[i] = get_bits(&gb, 8);
        for(i = 0; i <= stereo; i++)
            *samples8++ = pred[i];
        for(; i < unp_size; i++) {
            if(get_bits_left(&gb)<0)
                return -1;
            if(i & stereo){
                if(vlc[1].table)
                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[1] += sign_extend(h[1].values[res], 8);
                *samples8++ = av_clip_uint8(pred[1]);
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[0] += sign_extend(h[0].values[res], 8);
                *samples8++ = av_clip_uint8(pred[0]);
            }
        }
    }

    for(i = 0; i < 4; i++) {
        if(vlc[i].table)
            free_vlc(&vlc[i]);
        av_free(h[i].bits);
        av_free(h[i].lengths);
        av_free(h[i].values);
    }

    *got_frame_ptr   = 1;
    *(AVFrame *)data = s->frame;

    return buf_size;
}