[FFmpeg-devel] [PATCH v2] avcodec/pthread_frame, decode: allow errors to happen on draining

[Muhammad Faiz]

On Sat, Apr 29, 2017 at 6:18 AM, Muhammad Faiz <mfcc64 at gmail.com> wrote:
> On Sat, Apr 29, 2017 at 6:01 AM, Michael Niedermayer
> <michael at niedermayer.cc> wrote:
>> On Fri, Apr 28, 2017 at 11:23:10PM +0700, Muhammad Faiz wrote:
>>> On Fri, Apr 28, 2017 at 5:55 PM, Ronald S. Bultje <rsbultje at gmail.com> wrote:
>>> > Hi,
>>> >
>>> > On Fri, Apr 28, 2017 at 6:19 AM, Muhammad Faiz <mfcc64 at gmail.com> wrote:
>>> >>
>>> >> So, all frames and errors are correctly reported in order.
>>> >> Also limit the numbers of error during draining to prevent infinite loop.
>>> >>
>>> >> This fix fate failure with THREADS>=4:
>>> >>   make fate-h264-attachment-631 THREADS=4
>>> >> This also reverts a755b725ec1d657609c8bd726ce37e7cf193d03f.
>>> >>
>>> >> Suggested-by: wm4, Ronald S. Bultje, Marton Balint
>>> >> Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
>>> >> ---
>>> >>  libavcodec/decode.c        | 21 +++++++++++++++++++--
>>> >>  libavcodec/internal.h      |  3 +++
>>> >>  libavcodec/pthread_frame.c | 15 +++++++--------
>>> >>  3 files changed, 29 insertions(+), 10 deletions(-)
>>> >>
>>> >> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>>> >> index 6ff3c40..edfae55 100644
>>> >> --- a/libavcodec/decode.c
>>> >> +++ b/libavcodec/decode.c
>>> >> @@ -568,8 +568,24 @@ FF_ENABLE_DEPRECATION_WARNINGS
>>> >>          avctx->time_base = av_inv_q(av_mul_q(avctx->framerate,
>>> >> (AVRational){avctx->ticks_per_frame, 1}));
>>> >>  #endif
>>> >>
>>> >> -    if (avctx->internal->draining && !got_frame)
>>> >> -        avci->draining_done = 1;
>>> >> +    /* do not stop draining when got_frame != 0 or ret < 0 */
>>> >> +    if (avctx->internal->draining && !got_frame) {
>>> >> +        if (ret < 0) {
>>> >> +            /* prevent infinite loop if a decoder wrongly always return
>>> >> error on draining */
>>> >> +            /* reasonable nb_errors_max = maximum b frames + thread count
>>> >> */
>>> >> +            int nb_errors_max = 20 + (HAVE_THREADS &&
>>> >> avctx->active_thread_type & FF_THREAD_FRAME ?
>>> >> +                                avctx->thread_count : 1);
>>> >> +
>>> >> +            if (avci->nb_draining_errors++ >= nb_errors_max) {
>>> >> +                av_log(avctx, AV_LOG_ERROR, "Too many errors when
>>> >> draining, this is a bug. "
>>> >> +                       "Stop draining and force EOF.\n");
>>> >> +                avci->draining_done = 1;
>>> >> +                ret = AVERROR_BUG;
>>> >> +            }
>>> >> +        } else {
>>> >> +            avci->draining_done = 1;
>>> >> +        }
>>> >> +    }
>>> >
>>> >
>>> > Hm... I guess this is OK, it would be really nice to have a way of breaking
>>> > in developer builds (e.g. av_assert or so, although I guess technically this
>>> > could be enabled in prod builds also).
>>>
>>> Add av_assert2().
>>>
>>> >
>>> > Also, Marton suggested to return AVERROR_EOF, maybe handle that here also in
>>> > addition to ret=0?
>>>
>>> Modified.
>>>
>>> Updated patch attached.
>>>
>>> Thank's
>>
>>>  decode.c        |   23 +++++++++++++++++++++--
>>>  internal.h      |    3 +++
>>>  pthread_frame.c |   15 +++++++--------
>>>  3 files changed, 31 insertions(+), 10 deletions(-)
>>> d3049c52598070baa9566fc98a089111732595fa  0001-avcodec-pthread_frame-decode-allow-errors-to-happen-.patch
>>> From f684770e016fa36d458d08383065815882cbc7f8 Mon Sep 17 00:00:00 2001
>>> From: Muhammad Faiz <mfcc64 at gmail.com>
>>> Date: Fri, 28 Apr 2017 17:08:39 +0700
>>> Subject: [PATCH v3] avcodec/pthread_frame, decode: allow errors to happen on
>>>  draining
>>>
>>> So, all frames and errors are correctly reported in order.
>>> Also limit the number of errors during draining to prevent infinite loop.
>>> Also return AVERROR_EOF directly on EOF instead of only setting draining_done.
>>>
>>> This fix fate failure with THREADS>=4:
>>>   make fate-h264-attachment-631 THREADS=4
>>> This also reverts a755b725ec1d657609c8bd726ce37e7cf193d03f.
>>>
>>> Suggested-by: wm4, Ronald S. Bultje, Marton Balint
>>> Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
>>> ---
>>>  libavcodec/decode.c        | 23 +++++++++++++++++++++--
>>>  libavcodec/internal.h      |  3 +++
>>>  libavcodec/pthread_frame.c | 15 +++++++--------
>>>  3 files changed, 31 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>>> index 6ff3c40..fb4d4af 100644
>>> --- a/libavcodec/decode.c
>>> +++ b/libavcodec/decode.c
>>> @@ -568,8 +568,26 @@ FF_ENABLE_DEPRECATION_WARNINGS
>>>          avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1}));
>>>  #endif
>>>
>>> -    if (avctx->internal->draining && !got_frame)
>>> -        avci->draining_done = 1;
>>> +    /* do not stop draining when got_frame != 0 or ret < 0 */
>>> +    if (avctx->internal->draining && !got_frame) {
>>> +        if (ret < 0) {
>>> +            /* prevent infinite loop if a decoder wrongly always return error on draining */
>>> +            /* reasonable nb_errors_max = maximum b frames + thread count */
>>> +            int nb_errors_max = 20 + (HAVE_THREADS && avctx->active_thread_type & FF_THREAD_FRAME ?
>>> +                                avctx->thread_count : 1);
>>> +
>>> +            if (avci->nb_draining_errors++ >= nb_errors_max) {
>>> +                av_log(avctx, AV_LOG_ERROR, "Too many errors when draining, this is a bug. "
>>> +                       "Stop draining and force EOF.\n");
>>> +                avci->draining_done = 1;
>>> +                ret = AVERROR_BUG;
>>
>>> +                av_assert2(0);
>>
>> Please build with --assert-level=2
>> this triggers for the 2 files i sent you yesterday
>
> I've already dropped the updated patch.
>
> Thank's

Applied (PATCH v2)

Thank's