[x264-devel] Appending an iFrame to the start of a h264 video?

[Cary Fitzhugh]

Thanks for the reply!

I'll keep looking if you all think it is possible.
I may be getting tripped up by ffmpeg adding some header information onto the front. I'm not sure.

At least I have a clue that it may be possible.

Thanks so much,
Cary

Alex Giladi wrote:
> "cat movie1.264 movie2.264 > longer_movie.264 " should suffice, AFAIK.
> 
> On Wed, Jul 9, 2008 at 12:41 PM, Cary Fitzhugh <cfitzhugh at echo360.com> wrote:
>> Hello --
>>
>> I'm trying to figure out if there is a way to concatenate two h264 files without reencoding.
>>
>> I am making edits of longer h264 videos.
>> In order to make sure that my video starts on an iFrame - I want to use ffmpeg to encode a single frame at the start
>> time.  Then in a subsequent call - do a -vcodec copy on the rest of the edit.
>>
>> This provides me with 2 h264 movies.  One is 1 frame long and is an iframe.  The second movie is the rest of the edit.
>>
>> I do not understand the h264 codec well enough - which is why I'm writing you all.  It makes sense in my head, that if I
>> were to just concatenate the raw h264 files together and wrap it I should have a valid h264 file.
>>
>> In my movies I do not have B frames, just P and I frames.  My understanding is that P frames are only moving forward.
>> So prepending that initial i frame onto the front of the edit should work fine.
>>
>> I tried this, and when I combined the two it got very swirly and messed up on vlc.
>>
>> ANy ideas if this is possible?  I would really like to do this no matter how convoluted I need to get.  When I'm editing
>> 1 - 4 hour movies all the time I would rather not wait 20% of real time to make an edit - just for that first iframe.
>>
>> Thanks for any insight into this.
>>
>> Cary FitzHugh
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