Function smka_decode_frame

libavcodec/smacker.c:565–690

* Decode Smacker audio data */

 * Decode Smacker audio data
 */
static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    GetBitContext gb;
    HuffContext h[4];
    VLC vlc[4];
    int16_t *samples = data;
    int8_t *samples8 = 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 > *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++)