[FFmpeg-devel] [PATCH] avformat/hlsenc: Fix initial setting for start_pts

[Andreas Rheinhardt]

Hongcheng Zhong:
> ----- On Mar 5, 2020, at 11:38 PM, lq lq at chinaffmpeg.org wrote:
> 
>>> 2020年3月5日 下午9:41，Hongcheng Zhong <sj.hc_zhong at sjtu.edu.cn> 写道：
>>>
>>> This patch fixes Bug #8469
>>> If x264 baseline profile is used with other profiles,
>>> start_pts will be initialized to audio stream's first pts,
>>> while the duration is calculated based on video stream's pts.
>>> In this patch the start_pts is initialized with the correct stream's first pts.
>>>
>>> Signed-off-by: Hongcheng Zhong <sj.hc_Zhong at sjtu.edu.cn>
>>> ---
>>> libavformat/hlsenc.c | 10 +++++++++-
>>> 1 file changed, 9 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
>>> index f6dd894..3b2434f 100644
>>> --- a/libavformat/hlsenc.c
>>> +++ b/libavformat/hlsenc.c
>>> @@ -126,6 +126,7 @@ typedef struct VariantStream {
>>>     int has_video;
>>>     int has_subtitle;
>>>     int new_start;
>>> +    int start_pts_from_audio;
>>>     double dpp;           // duration per packet
>>>     int64_t start_pts;
>>>     int64_t end_pts;
>>> @@ -2274,9 +2275,15 @@ static int hls_write_packet(AVFormatContext *s, AVPacket
>>> *pkt)
>>>
>>>     if (vs->start_pts == AV_NOPTS_VALUE) {
>>>         vs->start_pts = pkt->pts;
>>> +        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
>>> +            vs->start_pts_from_audio = 1;
>>> +    }
>>> +    if (vs->start_pts_from_audio && st->codecpar->codec_type ==
>>> AVMEDIA_TYPE_VIDEO && vs->start_pts > pkt->pts) {
>>> +        vs->start_pts = pkt->pts;
>>> +        vs->start_pts_from_audio = 0;
>>>     }
>>>
>>> -   if (vs->has_video) {
>>> +    if (vs->has_video) {
>> What’s happen with this line?
>>>         can_split = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
>>>                     ((pkt->flags & AV_PKT_FLAG_KEY) || (hls->flags & HLS_SPLIT_BY_TIME));
>>>         is_ref_pkt = (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
>>>         (pkt->stream_index == vs->reference_stream_index);
>>> @@ -2751,6 +2758,7 @@ static int hls_init(AVFormatContext *s)
>>>         vs->sequence       = hls->start_sequence;
>>>         vs->start_pts      = AV_NOPTS_VALUE;
>>>         vs->end_pts      = AV_NOPTS_VALUE;
>>> +        vs->start_pts_from_audio = 0;
>>>         vs->current_segment_final_filename_fmt[0] = '\0';
>>>
>>>         if (hls->flags & HLS_SPLIT_BY_TIME && hls->flags & HLS_INDEPENDENT_SEGMENTS) {
>>> --
>>> 2.7.4
>>>
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> 
> Actually, this line is useless because that vs is initialized as all zero.
> Should I remove this line and submit this patch as v2 again? Thanks for your reply.

But vs->has_video is initialized to a potentially nonzero value in
hls_init().

- Andreas