I'm decoding/encoding the same mp4 (video/mp4) file using ffmpeg (libAV library) + libx264 encoder. For example, the original video file contains 182 frames:
[libx264 @ 0x7fb4a843ce00] frame I:2 Avg QP:17.95 size: 13834
[libx264 @ 0x7fb4a843ce00] frame P:180 Avg QP:19.90 size: 6297
but after the followig decoding/encoding I'm getting file contains 181 frames:
[libx264 @ 0x7fb4ac421dc0] frame I:2 Avg QP:17.93 size: 13627
[libx264 @ 0x7fb4ac421dc0] frame P:179 Avg QP:19.77 size: 5946
I've already tried to change AVCodecContext gop_size/max_b_frames/priv_data (profile, preset, tune, x264opts) and I've also read these posts and tried to solve my problem:
ffpmeg drops last frame when compressing from MP4 to MP4 (libx264)
ffmpeg/libx264 C API: frames dropped from end of short MP4
UPD: If I set framerate and timebase = 26/1 and 1/26 and more - frame doesn't drop.
UPD2: Solved!
//in function avformat_open_input() add AVDictionary *options:
av_dict_set(&options, "r", "25", 0);
av_dict_set(&options, "ignore_editlist", "1", 0);
I expected decoding/encoding videos with all the frames (without changed parameters).