Hi! As a part of figuring out the problem I have with ffplay <https://stackoverflow.com/questions/52390694/video-moves-sideways-when-captured-raw-from-camera-and-piped-into-ffplay/52399554#52399554>, I noticed, that ffmpeg adds 32 bytes to raw 0rgb frames when capturing from a camera (macOS 10.12):
$ ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 640x480 -i "0" -map 0:v -c copy -f rawvideo -vframes 1 /tmp/frame.0rgb $ wc -c /tmp/frame.0rgb 1228832 /tmp/frame.0rgb which is exactly 32 bytes larger than expected (1228800 = 640x480x4). This also holds for larger frame resolutions: $ ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 1280x720 -i "0" -map 0:v -c copy -f rawvideo -vframes 1 /tmp/frame.0rgb $ wc -c /tmp/frame.0rgb 3686432 /tmp/frame.0rgb Moreover, it's not an "initial header", but rather a per-frame header, because when I save 2 frames, the resulting size is 64 bytes larger: $ ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 1280x720 -i "0" -map 0:v -c copy -f rawvideo -vframes 2 /tmp/frame.0rgb $ wc -c /tmp/frame.0rgb 7372864 /tmp/frame.0rgb I believe this affects ffplay's preview, which results in "video scrolling" effect (see the link for my stackoverflow question above). Why does ffmpeg add 32 bytes for each frame and how can I work around it to drop it on the receiving end (ffplay)? Thanks -- Peter Gusev <https://www.linkedin.com/in/peter-gusev-8135441a/> *[email protected] <[email protected]>* *+1 213 587-27-48* *Research Scholar @ REMAP UCLA <http://www.remap.ucla.edu/home/about>Video streaming/ICN networks/Creative Coding/Interactive Media* *dj peetonn <https://soundcloud.com/peter-gusev>* _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
