[gst-devel] Tell me about y4menc and other encoders.

[wally_bkg]

Benjamin Schwartz wrote:
> 
> On 12/03/2010 04:53 PM, wally_bkg wrote:
>> I first tried: jpegenc, mpeg2enc, and theoraenc.  I could eliminate
>> mpeg2enc
>> from a combination of too high CPU load and too low video quality (using
>> only the defaults).
> 
> All of these elements take an argument that allows you to specify your
> desired bitrate/quality.  There's nothing especially great about the
> defaults, which may be incomparable from one element to another.
> 

I guess this is why video editors like Pitivi generally do a crappy job of
actually producing output -- expecting either the application developer, or
worse the end user, to be expert in encoding parameters instead of providing
reasonable defaults.  The default quality for theoraenc and jpegenc were
usable, the defaults fro mpeg2enc were so far from usable I wouldn't know
where to start changing things.



Benjamin Schwartz wrote:
> 
>> problem here is while the files play back fine in Totem, there is
>> something
>> wrong with them if I try to play them on a Windows system (that is set up
>> for MJPEG and OGG/Theora).
> 
> If you want help debugging this you'll need to be more specific about the
> playback system and the problem.  Latest VLC generally plays back Theora
> correctly under Windows.
> 

I was using the K-lite Codec pack and "Media Player Classic" on Windows.  As
I said, the system plays every MJPEG and OGV file I'd thrown at it until
these samples I created with gstreamer.  I downloaded VLC-win32 1.1.5  and
it plays the OGV file back OK.  I guess my Codec pack is out of date.  I was
worried something was wrong with the file headers  But VLC doesn't play the
MJPEG file, so maybe something is not setup correctly for avimux.


Benjamin Schwartz wrote:
> 
>> Then I discovered y4menc:
>> while it gives about 30X the file size of theoraenc it uses very little
>> CPU,
>> less than half of the jpegenc pipeline. 
> 
> y4m is uncompressed lossless raw video.  
> --Ben
> 

I was aware of this, but since a y4mdec seems to be missing I was wondering
how it was intended to be used since I couldn't seem to find a video file
format that would "wrap" it so seeking would work.  As I said, decodebin let
me play it back, got some playback speed glitches, but the images all looked
good and in proper sequence -- I was quite impressed with the handling of an
~10GB file on my 64-bit system.

Thanks for the link.


-- 
View this message in context: http://gstreamer-devel.966125.n4.nabble.com/Tell-me-about-y4menc-and-other-encoders-tp3071830p3076605.html
Sent from the GStreamer-devel mailing list archive at Nabble.com.