Function tdsc_decode_tiles

libavcodec/tdsc.c:385–454

Parse frame and either copy data or decode JPEG. */

/* Parse frame and either copy data or decode JPEG. */
static int tdsc_decode_tiles(AVCodecContext *avctx, int number_tiles)
{
    TDSCContext *ctx = avctx->priv_data;
    int i;

    /* Iterate over the number of tiles */
    for (i = 0; i < number_tiles; i++) {
        int tile_size;
        int tile_mode;
        int x, y, x2, y2, w, h;
        int ret;

        if (bytestream2_get_bytes_left(&ctx->gbc) < 4 ||
            bytestream2_get_le32(&ctx->gbc) != MKTAG('T','D','S','B') ||
            bytestream2_get_bytes_left(&ctx->gbc) < TDSB_HEADER_SIZE - 4) {
            av_log(avctx, AV_LOG_ERROR, "TDSB tag is too small.\n");
            return AVERROR_INVALIDDATA;
        }

        tile_size = bytestream2_get_le32(&ctx->gbc);
        if (bytestream2_get_bytes_left(&ctx->gbc) < tile_size + 24LL)
            return AVERROR_INVALIDDATA;

        tile_mode = bytestream2_get_le32(&ctx->gbc);
        bytestream2_skip(&ctx->gbc, 4); // unknown
        x = bytestream2_get_le32(&ctx->gbc);
        y = bytestream2_get_le32(&ctx->gbc);
        x2 = bytestream2_get_le32(&ctx->gbc);
        y2 = bytestream2_get_le32(&ctx->gbc);

        if (x < 0 || y < 0 || x2 <= x || y2 <= y ||
            x2 > ctx->width || y2 > ctx->height
        ) {
            av_log(avctx, AV_LOG_ERROR,
                   "Invalid tile position (%d.%d %d.%d outside %dx%d).\n",
                   x, y, x2, y2, ctx->width, ctx->height);
            return AVERROR_INVALIDDATA;
        }
        w = x2 - x;
        h = y2 - y;

        ret = av_reallocp(&ctx->tilebuffer, tile_size);
        if (!ctx->tilebuffer)
            return ret;

        bytestream2_get_buffer(&ctx->gbc, ctx->tilebuffer, tile_size);

        if (tile_mode == MKTAG('G','E','P','J')) {
            /* Decode JPEG tile and copy it in the reference frame */
            ret = tdsc_decode_jpeg_tile(avctx, tile_size, x, y, w, h);
            if (ret < 0)
                return ret;
        } else if (tile_mode == MKTAG(' ','W','A','R')) {
            if (3LL * w * h > tile_size)
                return AVERROR_INVALIDDATA;

            /* Just copy the buffer to output */
            av_image_copy_plane(ctx->refframe->data[0] + x * 3 +