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

[Steven Liu]

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)
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".

LGTM

Thanks
Steven