[FFmpeg-user] Fast encoding
Henk D. Schoneveld
belcampo at zonnet.nl
Fri Aug 14 14:58:24 CEST 2015
On 14 Aug 2015, at 14:46, Robin Lery <robinlery at gmail.com> wrote:
> Thank you for your guidance. Actual the videos that I'll be encoding are
> for web video, so I think the bit rate matters. And as for the threads I
> want to use all the threads possible. I think -threads 0 balance the loads
> across all the cores automatically. What would be the best ffmpeg command
> in your opinion for fast encoding with constant specified bit rates (i.e
> 500k and 1000k)?
ConstantBitrate is too much or too little
CRF/ConstantQuality is ….
> Thank you.
> On Thu, Aug 13, 2015 at 7:43 PM, Moritz Barsnick <barsnick at gmx.net> wrote:
>> On Thu, Aug 13, 2015 at 09:03:48 -0500, Steve Boyer wrote:
>>> On Wed, Aug 12, 2015 at 11:03 PM, Robin Lery <robinlery at gmail.com>
>>>> I know about presets but faster presets lose the video quality. Are
>>> It's my experience that CRF more directly affects the quality, and
>>> presets more influence filesize and encoding speed; a preset of slow
>>> will be ABOUT the same quality as veryfast but the bitrate between the
>>> two would be drastically different (in my opinion and eyes).
>> The presets were designed to trade off speed versus size, using the
>> same CRF and thereby (approximately) the same quality. But Robin is
>>> -maxrate 1000k
>> thereby limiting what the encoder can achieve in terms of quality.
>>> I've used -threads=1 successfully after input, before output file name.
>> Did Robin want to use more threads, or less? I understand ffmpeg
>> automatically tries to choose the right amount of threads.
>> (That said, my libx264 claims: "Threading capabilities: no", but I read
>> differing stuff on that.)
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