ffmpegthumbnailer CLI as well as libffmpegthumbnailer fail to produce a thumbnail for interlaced PNG images.
For example, when running
ffmpegthumbnailer -i a_difficult_situation.png -o a_difficult_situation.thumb.png
with the following image:
I get an empty file and this output in the terminal:
Seeking in video failed Operation not permitted, will use first frame.
Error: decodeVideoFrame() failed: frame not finished
I spent a while trying to fix the issue on my own, but I lack a good understanding of how libav is supposed to work.
I narrowed down the issue to MovieDecoder::getScaledVideoFrame() https://github.com/dirkvdb/ffmpegthumbnailer/blob/master/libffmpegthumbnailer/moviedecoder.cpp#L609
Where av_buffersink_get_frame() is called, returns AVERROR(EAGAIN), and when we try to call decodeVideoFrame() in the subsequent loop, there isn't actually any data left to decode.
If you don't have time to write a fix yourself, I would appreciate some precise pointers on how I could write a fix for the issue, thank you!
ffmpegthumbnailer CLI as well as libffmpegthumbnailer fail to produce a thumbnail for interlaced PNG images.
For example, when running
with the following image:
I get an empty file and this output in the terminal:
I spent a while trying to fix the issue on my own, but I lack a good understanding of how libav is supposed to work.
I narrowed down the issue to
MovieDecoder::getScaledVideoFrame()https://github.com/dirkvdb/ffmpegthumbnailer/blob/master/libffmpegthumbnailer/moviedecoder.cpp#L609Where
av_buffersink_get_frame()is called, returns AVERROR(EAGAIN), and when we try to calldecodeVideoFrame()in the subsequent loop, there isn't actually any data left to decode.If you don't have time to write a fix yourself, I would appreciate some precise pointers on how I could write a fix for the issue, thank you!