[FFmpeg-devel] [PATCH] lavf/dashenc: Fix segment duration overflow on fine time bases.

[Jeyapal, Karthick]

On 11/22/18 6:35 PM, Carl Eugen Hoyos wrote:
> 2018-11-22 7:43 GMT+01:00, Jeyapal, Karthick <kjeyapal at akamai.com>:
>>
>> On 11/20/18 11:03 PM, Andrey Semashev wrote:
>>> When stream time bases are very fine grained (e.g. nanoseconds), 32-bit
>>> segment duration may overflow for even for rather small segment duration
>>> (about 4 seconds long). Therefore we use 64-bit values for segment
>>> duration.
>>> ---
>>>  libavformat/dashenc.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
>>> index d151921175..8d0bc4baa2 100644
>>> --- a/libavformat/dashenc.c
>>> +++ b/libavformat/dashenc.c
>>> @@ -59,7 +59,7 @@ typedef struct Segment {
>>>      int64_t start_pos;
>>>      int range_length, index_length;
>>>      int64_t time;
>>> -    int duration;
>>> +    int64_t duration;
>>>      int n;
>>>  } Segment;
>>>
>>> @@ -428,7 +428,7 @@ static void output_segment_list(OutputStream *os,
>>> AVIOContext *out, AVFormatCont
>>>                      cur_time = seg->time;
>>>                      avio_printf(out, "t=\"%"PRId64"\" ", seg->time);
>>>                  }
>>> -                avio_printf(out, "d=\"%d\" ", seg->duration);
>>> +                avio_printf(out, "d=\"%"PRId64"\" ", seg->duration);
>>>                  while (i + repeat + 1 < os->nb_segments &&
>>>                         os->segments[i + repeat + 1]->duration ==
>>> seg->duration &&
>>>                         os->segments[i + repeat + 1]->time ==
>>> os->segments[i + repeat]->time + os->segments[i + repeat]->duration)
>>> @@ -1149,7 +1149,7 @@ static int dash_write_header(AVFormatContext *s)
>>>  }
>>>
>>>  static int add_segment(OutputStream *os, const char *file,
>>> -                       int64_t time, int duration,
>>> +                       int64_t time, int64_t duration,
>>>                         int64_t start_pos, int64_t range_length,
>>>                         int64_t index_length, int next_exp_index)
>>>  {
>>
>> LGTM.
>
> Please commit the patch if it is ok.
Sure. I am just waiting for 3 days to complete as per the ffmpeg developer guidelines.
Will push it tomorrow. Let me know if it is urgent for some reason, in which case I will push it earlier.
>
> Carl Eugen
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