[FFmpeg-user] Windows Media Player cannot play the file

[James Darnley]

On 2014-03-10 22:18, Spencer Graves wrote:
> On 3/10/2014 3:39 AM, James Darnley wrote:
>> As for uploading to youtube, just make the highest quality file.  They
>> will re-encode it anyway.  But if you are aiming to produce a file that
>> will play on any basic Windows installation you will want to read this:
>> http://ffmpeg.org/faq.html#Which-codecs-are-supported-by-Windows_003f

Just so we are clear.  None of this applies to a file you want to upload
to youtube.  It doesn't matter what you give it.  They will re-encode it
so it plays in browsers.

Uploading to youtube would be an easy way to not have to provide tech
support to some layperson about getting your video to play.

> Thanks for the reference. I'm still confused.
> 
> 
> 1. ‘mpeg1video’ produces .mpg only, which "should work on most Windows
> systems". This uses MPEG-1, which "due to its age ... is no longer
> covered by any patents and can thus be used without obtaining a licence
> or paying any fees", according to the Wikipedia article on MPEG-1. This
> sounds like a strong potential.

What question are you trying to ask here?  The FAQ means that you can
use mpeg1video (the as the codec in ffmpeg) but that you should output
to an mpg file (the format, file format, in ffmpeg).

It is old, meaning it won't retain much quality at "regular" bitrates by
today's standards and it is limited to specific combinations of frame
dimensions and frame rates.

> 2. We are "strongly advised to avoid ASF where possible." If I
> understand correctly, this includes the first four options listed there:
> ‘msmpeg4v2’, ‘msmpeg4’, ‘wmv1’, and ‘wmv2’. A similar concern may apply
> to the fifth option, 'mpeg4': AT&T actively "trying to sue companies
> such as Apple Inc. over alleged MPEG-4 patent infringement." (Wikipedia,
> "MPEG-4")

You can use msmpeg4v2 in an avi file.  asf is another name for wmv.
These both refer to the format not codecs and should be separate from
this patent shenanigans but may still fall under other patent shenanigans.

My non-legal, non-expert opinion is that you can't patent software.
Consult your own lawyer.

> 3. What codecs are used by default? If MPEG-1 video and Layer I/II
> audio, that sounds great. Wikipedia, "MPEG-1", says, "MPEG-1 video and
> Layer I/II audio is no longer covered by any patents."

The codecs ffmpeg uses by default vary with the (file) format you asked
for.  avi will use mpeg4.  mp4 will use libx264 if available.  mpg will
use mpeg1video  other will use others.  I'm not sure about the defaults
for audio.  I think many might be mp2.

ffmpeg prints all this information when you encode something so if you
are unsure, read the log.  Then if you don't know what some ffmpeg
jargon might be look it up or ask for help.

> 4. Also, is YUV420p a codec or something else?

Pixel format, as ffmpeg calls it.

Specifically it is Planar YCbCr with 4:2:0 Chroma Subsampling.  This can
be found elsewhere usually with YV12 and I420 fourCCs.


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