[FFmpeg-user] Running multiple ffmpeg commands with minimal loss in quality

[MrNice]

On 25/07/15 09:54, Francois Visagie wrote:
>> -----Original Message-----
>> From: ffmpeg-user [mailto:ffmpeg-user-bounces at ffmpeg.org] On Behalf Of
>> Michael Nolan
>> Sent: 25 July 2015 01:02
>> To: ffmpeg-user at ffmpeg.org
>> Subject: [FFmpeg-user] Running multiple ffmpeg commands with minimal
>> loss in quality
>>
>> Hi everyone,
>>
>> I'm writing a video editor which will push out a large json file that
>> includes the videos and a series of edits that were performed upon them. I
>> have a python application which parses the json and runs ffmpeg commands
>> to
>> do things like overlay, scale and trim videos, render text, render images,
>> etc.
>>
>> The biggest issue that I have is that the application that I run has to run
>> ffmpeg multiple times, thus re-encoding the video(s) and making the end
>> video look much lower quality than the original content. The original
>> videos are .webm and encoded using QTmuxingAppLibWebM-0.0.1.
>>
>> Is there any way that I can help prevent this sort of thing or is there any
>> existing tooling for taking a series of edits and running them in one
>> command (meaning I don't have to re-encode multiple times)?
>>
>> Any help would be appreciated.
> 
> The standard approach to this kind of issue is to use (as close to) losslessly encoded intermediate files as possible. I.e. either use a codec designed for lossless encoding such as "HuffYUV", or use something like x264 with "lossless" settings.
> 
>>

Sorry to interfere,
>
> The standard approach to this kind of issue is to use (as close to)
losslessly encoded intermediate files as possible. I.e. either use a
codec designed for lossless encoding such as "HuffYUV", or use something
like x264 with "lossless" settings.
>
Why do you add " " around lossless for x264. Is x264 still lossy even
with "lossless" setting?
BTW what is/are it/they?

Thanks François