Function decode_frame

libavcodec/nuv.c:130–248

}

static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                        AVPacket *avpkt) {
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    NuvContext *c = avctx->priv_data;
    AVFrame *picture = data;
    int orig_size = buf_size;
    int keyframe;
    int result;
    enum {NUV_UNCOMPRESSED = '0', NUV_RTJPEG = '1',
          NUV_RTJPEG_IN_LZO = '2', NUV_LZO = '3',
          NUV_BLACK = 'N', NUV_COPY_LAST = 'L'} comptype;

    if (buf_size < 12) {
        av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
        return -1;
    }

    // codec data (rtjpeg quant tables)
    if (buf[0] == 'D' && buf[1] == 'R') {
        int ret;
        // skip rest of the frameheader.
        buf = &buf[12];
        buf_size -= 12;
        ret = get_quant(avctx, c, buf, buf_size);
        if (ret < 0)
            return ret;
        rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height, c->lq, c->cq);
        return orig_size;
    }

    if (buf[0] != 'V' || buf_size < 12) {
        av_log(avctx, AV_LOG_ERROR, "not a nuv video frame\n");
        return -1;
    }
    comptype = buf[1];
    switch (comptype) {
        case NUV_RTJPEG_IN_LZO:
        case NUV_RTJPEG:
            keyframe = !buf[2]; break;
        case NUV_COPY_LAST:
            keyframe = 0; break;
        default:
            keyframe = 1; break;
    }
    // skip rest of the frameheader.
    buf = &buf[12];
    buf_size -= 12;
    if (comptype == NUV_RTJPEG_IN_LZO || comptype == NUV_LZO) {
        int outlen = c->decomp_size, inlen = buf_size;
        if (av_lzo1x_decode(c->decomp_buf, &outlen, buf, &inlen))
            av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
        buf = c->decomp_buf;
        buf_size = c->decomp_size;
    }
    if (c->codec_frameheader) {
        int w, h, q;
        if (buf_size < 12) {