[FFmpeg-user] Working with .YUV files

[Rhodri James]

On Tue, 14 Aug 2012 11:51:22 +0100, fb <fatemeh.bagherpour at gmail.com>  
wrote:

> Thank you so much for your reply :)
>
> At first, "YUVFilePlayer", I downloaded it from:
> http://www.softpedia.com/get/Multimedia/Graphic/Image-Convertors/YUV-File-Player.shtml
>
> let me exactly explain my problem, I have an input stream, mpeg2 or  
> h264, I
> want to transcode them (at least transrate). ffmpeg does it well, but I  
> want
> to do decoding and encoding separately, I mean:
>
> 1) Input.ts -> output1.YUV
> 2)output1.YUV -> output2.flv and with h264 as codec.
>
> There are several questions here :
> 1- when a player want to show a coded video (e.g h264), at first it  
> should
> decode it, and as I understood the output of decoding is "raw video"  
> (.yuv
> file). The player can't display such a file, so it would put it in a
> container. Right????

Wrong.  The player (I assume you mean YUVFilePlayer, but this applies to  
any other YUV viewer) doesn't invent anything for itself, nor should it.   
A YUV file contains only the pixel data, you have to tell the player  
everything else; the picture size, the pixel format, everything.  It's  
possible that the default pixel format ffmpeg chose (I don't off-hand know  
what that is, and you didn't include the complete, uncut console output  
that would tell us) isn't the same as the player's default pixel format,  
for example.  More likely, is the picture really 720x576 or some other  
video standard?

Also, as Carl pointed out, at this point you have lost the audio.  YUV  
files contain *only* the pixel data, remember.


> 2- As I understood, we have "raw h264" files that they are h264 coded
> streams with no container (I mean mkv, flv, 264 and ... by container).

Um.  Such things exist, but I'll be surprised if you have any of them.

> When
> we want them to be played, we should put them in a container too.  
> Right???

It significantly increases the chances of a random movie player  
understanding them.  It's also the only way to get audio and video  
together.

-- 
Rhodri James
Kynesim Ltd