For a long time, I can't figure out why 480p or 640x480 videos are stretched by YouTube. The output resolution is still the same but they seems to be rescaled in Y-axis. This should be much problem for your daily life video, but it is for screencasting. They looks like 90s homemade video in analogy, just terrible.
You can see an example in my previous video like this one. I used the following command to record:
The strange thing is 720p is fine, I don't understand what's going on and I won't bother to post in help forums because I doubt their engineer will read my question. YouTube Guru in forums? (Not sure about what YouTube staff name those volunteers) No offense, nah, but thanks anyway.
YouTube never mentioned problem with the video codec, no issue was reported except the file didn't have audio codec it recognizes. To YouTube: some videos are meant to have no audio tracks.
Anyway, if you know anything about the issue which I can still use AVC, please let me know. I am guessing it could be those encoding setting, but it's a long list and 99.999% of them I have no idea what they are for.
You can see an example in my previous video like this one. I used the following command to record:
~/p/x11grabr/x11grabr -b -s 640x480 | ffmpeg -f rawvideo -pix_fmt bgra -s 640x480 -r 25 -i - -vcodec libx264 -vpre lossless_ultrafast -strict experimental -threads 0 test.mkv ~ $ mediainfo test.mkv General Unique ID : 107803120395874480459111442715539922352 (0x511A2032421B3E79424266CB5EDBDDB0) Complete name : test.mkv Format : Matroska Format version : Version 2 File size : 584 KiB Duration : 2s 480ms Overall bit rate : 1 929 Kbps Writing application : Lavf52.111.0 Writing library : Lavf52.111.0 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High 4:4:4 [email protected] Format settings, CABAC : No Format settings, ReFrames : 1 frame Codec ID : V_MPEG4/ISO/AVC Duration : 2s 480ms Bit rate : 1 891 Kbps Width : 640 pixels Height : 480 pixels Display aspect ratio : 4:3 Frame rate mode : Variable Frame rate : 25.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.246 Stream size : 572 KiB (98%) Writing library : x264 core 115 Encoding settings : cabac=0 / ref=1 / deblock=1:0:0 / analyse=0x1:0 / me=dia / subme=0 / psy=0 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=0 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc=cqp / mbtree=0 / qp=0 Language : English Default : Yes Forced : NoToday I finally found a way to get around the problem by using WebM:
~/p/x11grabr/x11grabr -b -s 640x480 | ffmpeg -f rawvideo -pix_fmt bgra -s 640x480 -r 25 -i - test.webm ~ $ mediainfo test.webm General Unique ID : 162746949293301742131061222707439175632 (0x7A6FEC1BDD11DE98A5F24CEB620587D0) Complete name : test.webm Format : WebM Format version : Version 2 File size : 203 KiB Duration : 2s 40ms Overall bit rate : 815 Kbps Writing application : Lavf52.111.0 Writing library : Lavf52.111.0 Video ID : 1 Format : VP8 Codec ID : V_VP8 Duration : 2s 40ms Bit rate : 776 Kbps Width : 640 pixels Height : 480 pixels Display aspect ratio : 4:3 Frame rate : 25.000 fps Compression mode : Lossy Bits/(Pixel*Frame) : 0.101 Stream size : 193 KiB (95%) Language : English Default : Yes Forced : NoThe quality is poorer because it needs to tune a bit, but at least YouTube won't mess it up, here is an example output.
The strange thing is 720p is fine, I don't understand what's going on and I won't bother to post in help forums because I doubt their engineer will read my question. YouTube Guru in forums? (Not sure about what YouTube staff name those volunteers) No offense, nah, but thanks anyway.
YouTube never mentioned problem with the video codec, no issue was reported except the file didn't have audio codec it recognizes. To YouTube: some videos are meant to have no audio tracks.
Anyway, if you know anything about the issue which I can still use AVC, please let me know. I am guessing it could be those encoding setting, but it's a long list and 99.999% of them I have no idea what they are for.