[FFmpeg-devel] [PATCH v5] avformat/hls: Add option to retry failed segments for hls

[Gyan Doshi]

On 2022-10-21 02:49 pm, Steven Liu wrote:
> gnattu <gnattuoc at me.com> 于2022年10月20日周四 20:12写道：
>> Current HLS implementation simply skip a failed segment to catch up
>> the stream, but this is not optimal for some use cases like livestream
>> recording.
>> Add an option to retry a failed segment to ensure the output file is
>> a complete stream.
>>
>> Signed-off-by: gnattu <gnattuoc at me.com>
>> ---
>> v5 changed coding style as requested
>> v4 added documentation for the new seg_max_try option
>>
>>   doc/demuxers.texi |  4 ++++
>>   libavformat/hls.c | 15 ++++++++++++++-
>>   2 files changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/demuxers.texi b/doc/demuxers.texi
>> index 2b6dd86c2a..3e09a0f14e 100644
>> --- a/doc/demuxers.texi
>> +++ b/doc/demuxers.texi
>> @@ -401,6 +401,10 @@ Use HTTP partial requests for downloading HTTP segments.
>>
>>   @item seg_format_options
>>   Set options for the demuxer of media segments using a list of key=value pairs separated by @code{:}.
>> +
>> + at item seg_max_retry
>> +Maximum number of times to reload a segment on error, useful when segment skip on network error is not desired.
>> +Default value is 0.
>>   @end table
>>
>>   @section image2
>> diff --git a/libavformat/hls.c b/libavformat/hls.c
>> index e622425e80..2a5ffb927f 100644
>> --- a/libavformat/hls.c
>> +++ b/libavformat/hls.c
>> @@ -225,6 +225,7 @@ typedef struct HLSContext {
>>       int http_persistent;
>>       int http_multiple;
>>       int http_seekable;
>> +    int seg_max_retry;
>>       AVIOContext *playlist_pb;
>>       HLSCryptoContext  crypto_ctx;
>>   } HLSContext;
>> @@ -1472,6 +1473,7 @@ static int read_data(void *opaque, uint8_t *buf, int buf_size)
>>       int ret;
>>       int just_opened = 0;
>>       int reload_count = 0;
>> +    int segment_retries = 0;
>>       struct segment *seg;
>>
>>   restart:
>> @@ -1563,9 +1565,18 @@ reload:
>>               av_log(v->parent, AV_LOG_WARNING, "Failed to open segment %"PRId64" of playlist %d\n",
>>                      v->cur_seq_no,
>>                      v->index);
>> -            v->cur_seq_no += 1;
>> +            if (segment_retries >= c->seg_max_retry) {
>> +                av_log(v->parent, AV_LOG_WARNING, "Segment %"PRId64" of playlist %d failed too many times, skipping\n",
>> +                       v->cur_seq_no,
>> +                       v->index);
>> +                v->cur_seq_no++;
>> +                segment_retries = 0;
>> +            } else {
>> +                segment_retries++;
>> +            }
>>               goto reload;
>>           }
>> +        segment_retries = 0;
>>           just_opened = 1;
>>       }
>>
>> @@ -2549,6 +2560,8 @@ static const AVOption hls_options[] = {
>>           OFFSET(http_seekable), AV_OPT_TYPE_BOOL, { .i64 = -1}, -1, 1, FLAGS},
>>       {"seg_format_options", "Set options for segment demuxer",
>>           OFFSET(seg_format_opts), AV_OPT_TYPE_DICT, {.str = NULL}, 0, 0, FLAGS},
>> +    {"seg_max_retry", "Maximum number of times to reload a segment on error.",
>> +     OFFSET(seg_max_retry), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS},
>>       {NULL}
>>   };
>>
>> --
>> 2.37.0 (Apple Git-136)
>>
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>>
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> LGTM
>
> Thanks
> Steven

This doesn't appear to have been pushed.
Plan to push tomorrow.

Regards,
Gyan