[FFmpeg-devel] TrueHD track in EVO not playable/testable with ffplay

Ramiro Polla ramiro.polla
Thu Jul 23 23:01:03 CEST 2009


On Mon, Jul 20, 2009 at 7:30 PM, Justin Ruggles<justin.ruggles at gmail.com> wrote:
> Baptiste Coudurier wrote:
>> On 7/18/2009 3:15 PM, Ramiro Polla wrote:
>>> On Tue, Jul 14, 2009 at 5:26 PM, Michael Niedermayer<michaelni at gmx.at> wrote:
>>>> On Tue, Jul 14, 2009 at 02:59:13PM -0300, Ramiro Polla wrote:
>>>>> On Mon, Jul 13, 2009 at 6:02 PM, Justin Ruggles<justin.ruggles at gmail.com> wrote:
>>>>>> If you decide on using channels + request_channels + output_channels,
>>>>>> here is what I think should happen.
>>>>>>
>>>>>> demuxer/parser : set channels to the number of source channels,
>>>>>> completely ignoring request_channels.
>>>>>>
>>>>>> decoder : during init(), set channels to the number of source channels,
>>>>>> set output_channels to what it will output, trying if it can to honor
>>>>>> request_channels.
>>>>>>
>>>>>> The user can see if output_channels matches request_channels after
>>>>>> decoder init.
>>>>> And what shall the user do if output_channels has no value after decoder init?
>>>> he should call av_find_stream_info() either way and that should fill it in,
>>>> in theory ...
>>> I have a few more ideas:
>>> - av_find_stream_info() tests for output_channels if request_channels
>>> is set. this would require request_channels to be set before even
>>> opening the codec;
>>> - av_find_stream_info() fills possible channel combinations in
>>> coded_channels[] and the user chooses from that to set
>>> request_channels. In this case it would set coded_channels[0] = 2;
>>> coded_channels[1] = 6; coded_channels[2] = 0; or something like that.
>>
>> I really don't think av_find_stream_info you touch output_channels at
>> all, this is a decoding problem not a stream info problem.
>
> +1

Hmm... Now we have Michael who thinks av_find_stream_info() should get
information about request_channels, and Justin and Baptiste who think
otherwise.

Justin and Baptiste, you haven't answered this question:
>>>>> And what shall the user do if output_channels has no value after decoder init?

Ramiro Polla



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