[Libav-user] get frame type

[Robert Krüger]

On Tue, Mar 20, 2012 at 1:43 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> Robert Krüger <krueger at ...> writes:
>
>> > Did you try to read avFrame->pict_type ?
>> >
>> does this field have any meaning for h.264? I thought a frame could
>> consist of a mixture of B- P- and I-slices. What is the policy of the
>> h.264 decoder to set this field currently? I haven't checked recently
>> but I remember it to have weird values for the h.264 files I checked.
>
> Could you point me to the bug report?
> The decoder sets the value so I would expect it to be correct.
>

haven't filed a bug report but I can check if I can reproduce it and do that.

my question was rather if the field _can_ make sense for h.264 as I
have not found anything in the h.264 spec saying that a frame cannot
contain a mixture of I, P, B (and other) slices. What would the value
of the field then be? Only set to a value, if all slices of the frame
are of the same type (which then should be documented somewhere)? I
don't know if this is relevant for practical purposes, because I do
not know if those streams exist in the wild but AFAICS the spec allows
this.