[FFmpeg-user] Help with transcoding a vid from 1280x720 to highest quality HD 1920x1080

[Henk D. Schoneveld]

On 21 Mar 2016, at 18:57, jd1008 <jd1008 at gmail.com> wrote:

> 
> 
> On 03/21/2016 09:51 AM, Moritz Barsnick wrote:
>> On Sun, Mar 20, 2016 at 11:36:17 -0600, jd1008 wrote:
>> 
>>> highest quality HD 1920x1080
>> You should know better by now to be more specific. E.g. do you have any
>> restriction when it comes to codec? Time to convert? File size?
>> 
>> The best quality with the smallest effort can indeed be achieved if you
>> let the player/client rescale. I know that some rescalers are bad (I
>> own at least one :-P), so you may have a reason.
>> 
>> Rescaling on source level implies reencoding. "Highest quality" can
>> strictly only be achieved if you re-encode to a lossless codec (or
>> codec variant), at the cost of large files/large bandwidth. does your
>> client even understand lossless codecs? Are you okay with large
>> bandwidth????
>> 
>> Even if "lossy" is okay, to achieve similar quality (despite no
>> information being added when upscaling), you need more bandwidth than
>> the original. You will have to experiment what fits your need.
>> 
>> All those caveats aside:
>> $ ffmpeg -i EarthView.mp4 -vf scale=hd1080 -c:v libx264 -c:a copy EarthView.large.mp4
>> 
>> If the quality is not sufficient, add "-crf NN" as output (codec)
>> option, and choose a smaller number for NN than the default 23.
>> 
>> I could give better advice if I knew what you were aiming for...
>> 
>> Moritz
> Thank you Moritz.
> 
> Using the command you provided.
> So far, it has transcoded this much:
> frame=45418 fps=6.8 q=28.0 size=  640737kB time=00:31:34.44 bitrate=2770.7kbits/s
> 
> I tried to play the partialy transcoded file (not sure if that is the right thing to do),
That’s not possible for mp4 files. Only when finished, or you have to use the mpeg2ts container format.
> and I got just a lot of changing colored tiny squares and numerous messages of:
> 
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=65
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=65
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=94
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=66
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=68
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=81
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=65
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=65
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=67
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=66
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=91
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=65
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=74
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=64
> [dvvideo @ 0x7fdfee20ff20]AC EOB marker is absent pos=101
> 
> PS: Using ffmpeg-2.6.8-1.fc22.x86_64
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user