[FFmpeg-devel] [PATCH] pthread_frame: ignore errors during draining

[Muhammad Faiz]

On Tue, Apr 25, 2017 at 4:09 PM, Hendrik Leppkes <h.leppkes at gmail.com> wrote:
> On Tue, Apr 25, 2017 at 4:32 AM, Muhammad Faiz <mfcc64 at gmail.com> wrote:
>> On Tue, Apr 25, 2017 at 1:57 AM, wm4 <nfxjfg at googlemail.com> wrote:
>>> This is needed to get compatibility with the behavior before the
>>> recent decode.c restructuring merge, and fixes fate failures with
>>> this:
>>>
>>>   make fate-h264-attachment-631 THREADS=32
>>>
>>> For every 4 threads, a frame is dropped at the point at which
>>> draining is initialized. The problem starts at THREADS=4.
>>>
>>> This patch "fixes" it by ignoring errors during draining (if there
>>> is a frame to be returned), but there is probably a deeper cause
>>> and/or a better fix for this. I haven't looked closer at this, but
>>> was asked to send this patch for discussion.
>>> ---
>>>  libavcodec/pthread_frame.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
>>> index 13d682842d..e7fa503adf 100644
>>> --- a/libavcodec/pthread_frame.c
>>> +++ b/libavcodec/pthread_frame.c
>>> @@ -548,7 +548,7 @@ int ff_thread_decode_frame(AVCodecContext *avctx,
>>>      fctx->next_finished = finished;
>>>
>>>      /* return the size of the consumed packet if no error occurred */
>>> -    if (err >= 0)
>>> +    if (err >= 0 || (!avpkt->size && *got_picture_ptr))
>>
>> Probably (*got_picture_ptr && p->result >= 0)
>> So error is not ignored.
>>
>
> Isnt the entire point of this to ignore errors during draining?

wm4 stated that probably there is a better fix, and not ignoring error
is a better fix.
My point is that when a frame is retuned, propagate error from the
thread that return it,
not from another thread. More clearly
if (*got_picture_ptr) err = p->result