Carl Eugen Hoyos wrote > In your original email, you wrote that PSNR was ok > if the first (duplicated) frame was removed iirc.
Actually, this got confused with another problem with encoding to mpeg2 which I already figured out. The real problem was not here. Sorry. :) The real issue with avi decoding was found out by dissecting the avi headers and comparing them side by side with the one VirtualDub generated. Here is part of the header that VirtualDub generated: offset=0xAC header_size: 40 image_width: 512 image_height: 512 number_of_planes: 1 bits_per_pixel: 24 compression_type: 0 And here the same part that FFmpeg generated: offset=0xAC header_size: 40 image_width: 512 image_height: -512 number_of_planes: 1 bits_per_pixel: 24 compression_type: 0 The crucial difference is a negative image_height, indicating that the image content is upside down. The PSNR calculator did not notice this and so, because the original avi had a positive height and the comparison avi had a negative height, bad PSNRs would result. Carl Eugen Hoyos wrote > Could you elaborate on "different version"? I hope the above was sufficient. :) "Different version" means that the two AVIs that were compared with the PSNR calculator had their contents in different order. Both were BGR24 uncompressed AVIs. Frame accurately the same, just their byte content was not in the same order. Bottom line, the fault was in the PSNR calculator that should have alerted me. -- View this message in context: http://ffmpeg-users.933282.n4.nabble.com/Decode-to-BGR24-avi-tp4656854p4669771.html Sent from the FFmpeg-users mailing list archive at Nabble.com. _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
