[x264-devel] Issues with intra refresh?

BugMaster BugMaster at narod.ru
Mon Jan 16 22:48:49 CET 2012


On Mon, 16 Jan 2012 10:30:30 +0000, Robert Logue wrote:
> Yes it is a single threaded encode. I am using libx264.so.120. I was 
> initially using gstreamer to transcode videos when I discovered this 
> problem, I would hope gstreamer would re initialize the variables. I 
> have only altered the x264.c file to reproduce the issue without any 
> other component in the way. I am not a x264 programmer so not sure if I
> have re-initialized the variables correctly, it could be I haven't. 
> That's why I am here to see if it is a bug or an issue with something I
> am doing.

> Robert


> On 13/01/12 18:34, Toby wrote:
>> Question is similar to the deterministic discussion here:
>> http://forums.hexus.net/pc-hardware/118246-x264-video-encoding-benchmark-4.html
>>
>> For ref, veryfast USED to mean:
>> subme 1, ref 1, me dia, partitions i8x8,i4x4, trellis 0, weightp 0,
>> no-mixed-refs, no-mbtree
>>
>> This appears to be a single threaded encode, correct?
>>
>> What version of libx264? Are you re-initializing every variable that
>> remains across your two encodes?
>>
>> On Thu, Jan 12, 2012 at 11:51 AM, Robert Logue
>> <robert.logue at openwave.com>  wrote:
>>> I forgot to add I am using libx264.so.120
>>>
>>>
>>> On 12/01/12 16:37, Robert Logue wrote:
>>>> Hello,
>>>>
>>>> When I was running a test harness to go to youtube and download random
>>>> videos and transcode I found an issue. The issue is with intra-refresh
>>>> turned on libx264 gives back different video for the same input video
>>>> and params. This only seems to occur when the 1 process does multiple
>>>> transcodes of the same file.
>>>>
>>>> To test this I altered the x264.c file to transcode the same input file
>>>> twice and as output I got two different video files different file size
>>>> and different frame data.
>>>>
>>>> The command I used was
>>>>
>>>> /spare/x264/install/bin/x264 --preset=veryfast --bitrate=300
>>>> --tune=zerolatency --profile=baseline --intra-refresh --vbv-maxrate=300
>>>> --vbv-bufsize=12000 --ipratio=0.4 --qpmin=10  -o ./output.mp4 ./input.mp4
>>>>
>>>> and the video can be found here
>>>>
>>>> http://199.91.152.89/nhnunbt586kg/5xzsdnshfcgj459/tram.mp4
>>>>
>>>> Note the video was downloaded by a random test harness and is quiet
>>>> offensive. If possible it should not be watched and if watched the sound
>>>> should be turned down.
>>>>
>>>> I was on the web chat earlier and the guys on there indicated that this
>>>> could be a bug. Is there any where else to raise this or is here ok?
>>>>
>>>> Thanks
>>>>
>>>> Robert

Try with attached patch. It should probably fix your issue.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Fix-use-of-uninitialized-values-with-intra-refresh.diff
Type: application/octet-stream
Size: 926 bytes
Desc: not available
URL: <http://mailman.videolan.org/pipermail/x264-devel/attachments/20120117/310ddc76/attachment.obj>


More information about the x264-devel mailing list