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] = { { 0 } };
    VLC vlc[4]       = { { 0 } };
    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);
    }
    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];
    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) {
        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(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 {
        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(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)
            ff_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;
}
['static int smka_decode_frame(AVCodecContext *avctx, void *data,\n                             int *got_frame_ptr, AVPacket *avpkt)\n{\n    SmackerAudioContext *s = avctx->priv_data;\n    const uint8_t *buf = avpkt->data;\n    int buf_size = avpkt->size;\n    GetBitContext gb;\n    HuffContext h[4] = { { 0 } };\n    VLC vlc[4]       = { { 0 } };\n    int16_t *samples;\n    uint8_t *samples8;\n    int val;\n    int i, res, ret;\n    int unp_size;\n    int bits, stereo;\n    int pred[2] = {0, 0};\n    if (buf_size <= 4) {\n        av_log(avctx, AV_LOG_ERROR, "packet is too small\\n");\n        return AVERROR(EINVAL);\n    }\n    unp_size = AV_RL32(buf);\n    init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);\n    if(!get_bits1(&gb)){\n        av_log(avctx, AV_LOG_INFO, "Sound: no data\\n");\n        *got_frame_ptr = 0;\n        return 1;\n    }\n    stereo = get_bits1(&gb);\n    bits = get_bits1(&gb);\n    if (stereo ^ (avctx->channels != 1)) {\n        av_log(avctx, AV_LOG_ERROR, "channels mismatch\\n");\n        return AVERROR(EINVAL);\n    }\n    if (bits && avctx->sample_fmt == AV_SAMPLE_FMT_U8) {\n        av_log(avctx, AV_LOG_ERROR, "sample format mismatch\\n");\n        return AVERROR(EINVAL);\n    }\n    s->frame.nb_samples = unp_size / (avctx->channels * (bits + 1));\n    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {\n        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\\n");\n        return ret;\n    }\n    samples  = (int16_t *)s->frame.data[0];\n    samples8 =            s->frame.data[0];\n    for(i = 0; i < (1 << (bits + stereo)); i++) {\n        h[i].length = 256;\n        h[i].maxlength = 0;\n        h[i].current = 0;\n        h[i].bits = av_mallocz(256 * 4);\n        h[i].lengths = av_mallocz(256 * sizeof(int));\n        h[i].values = av_mallocz(256 * sizeof(int));\n        skip_bits1(&gb);\n        smacker_decode_tree(&gb, &h[i], 0, 0);\n        skip_bits1(&gb);\n        if(h[i].current > 1) {\n            res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,\n                    h[i].lengths, sizeof(int), sizeof(int),\n                    h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);\n            if(res < 0) {\n                av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\\n");\n                return -1;\n            }\n        }\n    }\n    if(bits) {\n        for(i = stereo; i >= 0; i--)\n            pred[i] = sign_extend(av_bswap16(get_bits(&gb, 16)), 16);\n        for(i = 0; i <= stereo; i++)\n            *samples++ = pred[i];\n        for(; i < unp_size / 2; i++) {\n            if(i & stereo) {\n                if(vlc[2].table)\n                    res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val  = h[2].values[res];\n                if(vlc[3].table)\n                    res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val |= h[3].values[res] << 8;\n                pred[1] += sign_extend(val, 16);\n                *samples++ = av_clip_int16(pred[1]);\n            } else {\n                if(vlc[0].table)\n                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val  = h[0].values[res];\n                if(vlc[1].table)\n                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val |= h[1].values[res] << 8;\n                pred[0] += sign_extend(val, 16);\n                *samples++ = av_clip_int16(pred[0]);\n            }\n        }\n    } else {\n        for(i = stereo; i >= 0; i--)\n            pred[i] = get_bits(&gb, 8);\n        for(i = 0; i <= stereo; i++)\n            *samples8++ = pred[i];\n        for(; i < unp_size; i++) {\n            if(i & stereo){\n                if(vlc[1].table)\n                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                pred[1] += sign_extend(h[1].values[res], 8);\n                *samples8++ = av_clip_uint8(pred[1]);\n            } else {\n                if(vlc[0].table)\n                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                pred[0] += sign_extend(h[0].values[res], 8);\n                *samples8++ = av_clip_uint8(pred[0]);\n            }\n        }\n    }\n    for(i = 0; i < 4; i++) {\n        if(vlc[i].table)\n            ff_free_vlc(&vlc[i]);\n        av_free(h[i].bits);\n        av_free(h[i].lengths);\n        av_free(h[i].values);\n    }\n    *got_frame_ptr   = 1;\n    *(AVFrame *)data = s->frame;\n    return buf_size;\n}', 'static inline void init_get_bits(GetBitContext *s, const uint8_t *buffer,\n                                 int bit_size)\n{\n    int buffer_size = (bit_size+7)>>3;\n    if (buffer_size < 0 || bit_size < 0) {\n        buffer_size = bit_size = 0;\n        buffer = NULL;\n    }\n    s->buffer       = buffer;\n    s->size_in_bits = bit_size;\n#if !UNCHECKED_BITSTREAM_READER\n    s->size_in_bits_plus8 = bit_size + 8;\n#endif\n    s->buffer_end   = buffer + buffer_size;\n    s->index        = 0;\n}', 'static inline unsigned int get_bits1(GetBitContext *s)\n{\n    unsigned int index = s->index;\n    uint8_t result = s->buffer[index>>3];\n#ifdef BITSTREAM_READER_LE\n    result >>= index & 7;\n    result &= 1;\n#else\n    result <<= index & 7;\n    result >>= 8 - 1;\n#endif\n#if !UNCHECKED_BITSTREAM_READER\n    if (s->index < s->size_in_bits_plus8)\n#endif\n        index++;\n    s->index = index;\n    return result;\n}']