[FFmpeg-devel] [PATCH] Wrong duration in TS container (Ticket #1836)

[Steven Liu]

2012/10/21 Steven Liu <lingjiujianke at gmail.com>:
> 2012/10/21 Heesuk Jung <heesuk.jung at lge.com>:
>> Fix indentation.
>>
>> From 2723ad65908531d136b828e4c9e615104a12beb8 Mon Sep 17 00:00:00 2001
>> From: Heesuk Jung <heesuk.jung at lge.com>
>> Date: Sun, 21 Oct 2012 13:21:23 +0900
>> Subject: [PATCH] Wrong duration in TS container (Ticket #1836)
>>
>> Libavformat somtimes get wrong duration in some TS conatiner.
>> Please refer the problem description and file link in Ticket #1836.
>> (http://ffmpeg.org/trac/ffmpeg/ticket/1836)
>>
>> I have just modified 2 point as below.
>>
>> 1. Duration determination considering time diff and file size / bit rate.
>>
>> Duration is determined base on PTS time diff (end time - start ime) but
>> sometime is unreasonably so big.
>> I suggest that don't beleive duration based on PTS time diff
>> if time diff is bigger than hueristic value (file size / average bit rate *
>> 2).
>>
>> 2. Change condition when estimate_timings_from_pts is called.
>>
>> The estimate_timings_from_pts function is designed for MPEG-PS.
>> And so I changed condition from MPEG-TS to MPEG-PS
>> ---
>>  libavformat/utils.c |   32 +++++++++++++++++++++++++++++---
>>  1 files changed, 29 insertions(+), 3 deletions(-)
>>  mode change 100644 => 100755 libavformat/utils.c
>>
>> diff --git a/libavformat/utils.c b/libavformat/utils.c
>> old mode 100644
>> new mode 100755
>> index 745dcaa..d322907
>> --- a/libavformat/utils.c
>> +++ b/libavformat/utils.c
>> @@ -2035,6 +2035,29 @@ static int has_duration(AVFormatContext *ic)
>>  }
>>
>>  /**
>> + * examine if estimation from pts difference(end pts - start pts) is valid
>> or not.
>> + * determine invalid duration if pts difference is un reasonably bigger
>> than file size/average bit rate.
>> + * hueristically suggest  limit_filesize_multiple that means double file
>> size
>> + * @return 1 if time_diff (end_time - start_time) is valid.
>> + *         0 if time_diff (end_time - start_time) is not valid.
>> + */
>> +static int valid_duration_from_pts(const int64_t start_time, const int64_t
>> end_time,
>> +                                    const int64_t filesize, int const
>> bit_rate)
>> +{
>> +    const uint8_t limit_filesize_multiple = 2;
>> +    const int64_t time_diff = end_time - start_time;
>> +
>> +    if (bit_rate != 0) {
>> +        if (time_diff >
>> (filesize*8/bit_rate*limit_filesize_multiple*1000000)) {
>> +            return 0;
>> +        }
>> +        return 1;
>> +    } else {
>> +        return 0;
>> +    }
>> +}
>> +
>> +/**
>>   * Estimate the stream timings from the one of each components.
>>   *
>>   * Also computes the global bitrate if possible.
>> @@ -2077,8 +2100,11 @@ static void update_stream_timings(AVFormatContext
>> *ic)
>>
>>      if (start_time != INT64_MAX) {
>>          ic->start_time = start_time;
>> -        if (end_time != INT64_MIN)
>> -            duration = FFMAX(duration, end_time - start_time);
>> +        if (end_time != INT64_MIN) {
>> +            if (valid_duration_from_pts(start_time, end_time,
>> avio_size(ic->pb), ic->bit_rate)) {
>> +                duration = FFMAX(duration, end_time - start_time);
>> +            }
>> +        }
>>      }
>>      if (duration != INT64_MIN && duration > 0 && ic->duration ==
>> AV_NOPTS_VALUE) {
>>          ic->duration = duration;
>> @@ -2233,7 +2259,7 @@ static void estimate_timings(AVFormatContext *ic,
>> int64_t old_offset)
>>      }
>>
>>      if ((!strcmp(ic->iformat->name, "mpeg") ||
>> -         !strcmp(ic->iformat->name, "mpegts")) &&
>> +         !strcmp(ic->iformat->name, "mpegps")) &&
>>          file_size && ic->pb->seekable) {
>>          /* get accurate estimate from the PTSes */
>>          estimate_timings_from_pts(ic, old_offset);
>> --
>> 1.7.0.4
>>
>>
> This patch is useful for me.
>
> Thanks  Heesuk Jung

Hi Jung

    How to check this patch?
    I have try it, but the duration always wrong.