Need some help in understanding this problem, and if there's any way to avoid it.
I notice some videos got "pressed" after using ffmpeg, even using a simple -map command.
The original video looks like this:
...with the video properties (as captured by VLC):
Stream 0 Codec: H264-MPEG-4 AVC (part 10)(avc1) Language: English Type: Video Video resolution: 718x478 Buffer dimensions: 720x480 Frame rate: 23.976215 Decoded format: Orientation: Top left Color primaries: ITU-R BT.601 (525 lines, 60 Hz) Color transfer function: ITU-R BT.709 Color space: ITU-R BT.601 Range Chroma location: left
Output from FFmpeg:
Stream #0:0(eng): Video: h264 (High), yuv420p(tv, smpte170m/smpte170m/bt709, progressive), 718x478 [SAR 8:9 DAR 2872:2151], SAR 223:251 DAR 80057:59989, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
However, after using the following FFmpeg command on the video (to remove an extra subtitle):
ffmpeg -i a.mkv -map 0:v -c:v copy -map 0:a -c:a copy -map 0:2 -c:s copy a1.mkv
...the new video (a1.mkv) becomes like this:
The strange thing is that the video properties remain the same: resolution, scale, etc., (based on the VLC and FFmpeg output shown above).
Anyone know why is this and how to avoid it? Is the original video "corrupted" in the first place?