The first byte contains compression level together with keyframe status. When a frame is not interpreted correctly, its data is summed to the reference, and would degrade over time, producing an incorrect result.
Signed-off-by: Vittorio Giovara <[email protected]> --- libavcodec/screenpresso.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/libavcodec/screenpresso.c b/libavcodec/screenpresso.c index af678cd..74b2f4b 100644 --- a/libavcodec/screenpresso.c +++ b/libavcodec/screenpresso.c @@ -115,12 +115,11 @@ static int screenpresso_decode_frame(AVCodecContext *avctx, void *data, return AVERROR_INVALIDDATA; } - /* Basic sanity check, but not really harmful */ - if (avpkt->data[0] != 0x73 && avpkt->data[0] != 0x72) - av_log(avctx, AV_LOG_WARNING, "Unknown header 0x%02X\n", avpkt->data[0]); - - keyframe = (avpkt->data[0] == 0x73); + /* Compression level and keyframe information */ + av_log(avctx, AV_LOG_DEBUG, "Compression level %d\n", avpkt->data[0] >> 4); + keyframe = (avpkt->data[0] & 0x0F) == 3; component_size = ((avpkt->data[1] >> 2) & 0x03) + 1; + /* Pixel size */ switch (component_size) { case 2: -- 2.7.3 _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
