[FFmpeg-devel] [PATCH] flv set pts

[Baptiste Coudurier]

Michael Niedermayer wrote:
> On Tue, Sep 30, 2008 at 11:28:45AM -0700, Baptiste Coudurier wrote:
>> Hi,
>>
>> Michael Niedermayer wrote:
>>> On Mon, Sep 29, 2008 at 07:56:17PM -0700, Baptiste Coudurier wrote:
>>>> Baptiste Coudurier wrote:
>>>>> Hi,
>>>>>
>>>>> $subject.
>>>>>
>>>> Scratch old patch, this one should be correct.
>>> can you post some example input&output pts & dts values for some file
>>> with b frames.
>>> I suspicion would be that the patch is not completely correct but this
>>> should be more obvious from a list of timestamps and frame types.
>>>
>> Well, I didn't find any having < 0 cts yet, however it has been said
>> that cts is signed like in .mov, so code is assuming that.
>>
>> Files generated by FFmpeg does not have < 0 cts.
>>
>> Patch is doing the same as the .mov demuxer excepts that we cannot know
>> in advance while we can in .mov, though it misses has_b_frames = 1, I
>> can see, not harmful though.
>>
>> What do you think could be wrong ? I'll try to find a file in the mean time.
> 
> Well
> if we take as example normal mpeg2 style IPB then
>         IPBBPBB
> dts:    0123456
> pts:    1423756
> would be correct
> 
> now if dts where increased by one:
> 
>         IPBBPBB
> dts:    1234567
> pts:    1423756
> 
> then this would be wrong, and not only the ones for the B frames
> would be wrong but all would be. That is for example if the I frame
> is feeded at time 1 into the decoder then it will be output at time 2 not 1.
> 

Humm of course yes, and in your situation, cts will be -1 for the third
frame to achieve dts 3 and pts 2, I don't see what you mean, the check
is indeed for cts < 0.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
Smartjog USA Inc.                                http://www.smartjog.com
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