Function tdsc_decode_jpeg_tile

libavcodec/tdsc.c:342–382

Invoke the MJPEG decoder to decode the tile. */

/* Invoke the MJPEG decoder to decode the tile. */
static int tdsc_decode_jpeg_tile(AVCodecContext *avctx, int tile_size,
                                 int x, int y, int w, int h)
{
    TDSCContext *ctx = avctx->priv_data;
    int ret;

    /* Prepare a packet and send to the MJPEG decoder */
    av_packet_unref(ctx->jpkt);
    ctx->jpkt->data = ctx->tilebuffer;
    ctx->jpkt->size = tile_size;

    ret = avcodec_send_packet(ctx->jpeg_avctx, ctx->jpkt);
    if (ret < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error submitting a packet for decoding\n");
        return ret;
    }

    ret = avcodec_receive_frame(ctx->jpeg_avctx, ctx->jpgframe);
    if (ret < 0 || ctx->jpgframe->format != AV_PIX_FMT_YUVJ420P ||
        w > ctx->jpgframe->width || h > ctx->jpgframe->height) {
        av_log(avctx, AV_LOG_ERROR,
               "JPEG decoding error (%d).\n", ret);

        /* Normally skip, error if explode */
        if (avctx->err_recognition & AV_EF_EXPLODE)
            return AVERROR_INVALIDDATA;
        else
            return 0;
    }

    /* Let's paint onto the buffer */
    tdsc_blit(ctx->refframe->data[0] + x * 3 + ctx->refframe->linesize[0] * y,
              ctx->refframe->linesize[0],
              ctx->jpgframe->data[0], ctx->jpgframe->linesize[0],
              ctx->jpgframe->data[1], ctx->jpgframe->data[2],
              ctx->jpgframe->linesize[1], w, h);

    av_frame_unref(ctx->jpgframe);

    return 0;
}

/* Parse frame and either copy data or decode JPEG. */
static int tdsc_decode_tiles(AVCodecContext *avctx, int number_tiles)