[FFmpeg-devel] [PATCH v5 1/2] avformat: refactor ff_stream_encode_params_copy() to ff_stream_params_copy()
Pierre-Anthony Lemieux
pal at sandflow.com
Fri Aug 5 02:08:28 EEST 2022
On Thu, Aug 4, 2022 at 3:22 PM Andreas Rheinhardt
<andreas.rheinhardt at outlook.com> wrote:
>
> Pierre-Anthony Lemieux:
> > On Thu, Aug 4, 2022 at 10:15 AM Andreas Rheinhardt
> > <andreas.rheinhardt at outlook.com> wrote:
> >>
> >> Pierre-Anthony Lemieux:
> >>> On Thu, Aug 4, 2022 at 9:53 AM Andreas Rheinhardt
> >>> <andreas.rheinhardt at outlook.com> wrote:
> >>>>
> >>>> pal at sandflow.com:
> >>>>> From: Pierre-Anthony Lemieux <pal at palemieux.com>
> >>>>>
> >>>>> As discussed at https://ffmpeg.org/pipermail/ffmpeg-devel/2022-July/298491.html.
> >>>>> Note that ff_stream_params_copy() does not copy:
> >>>>> * the index field
> >>>>> * the attached_pic if its size is 0
> >>>>>
> >>>>> Addresses http://ffmpeg.org/pipermail/ffmpeg-devel/2022-August/299514.html
> >>>>>
> >>>>> ---
> >>>>> libavformat/avformat.c | 40 ++++++++++++++++++++++++++++++++++++++++
> >>>>> libavformat/fifo.c | 2 +-
> >>>>> libavformat/internal.h | 12 ++++++++++++
> >>>>> libavformat/mux.h | 9 ---------
> >>>>> libavformat/mux_utils.c | 28 ----------------------------
> >>>>> libavformat/segment.c | 2 +-
> >>>>> libavformat/tee.c | 2 +-
> >>>>> libavformat/webm_chunk.c | 2 +-
> >>>>> 8 files changed, 56 insertions(+), 41 deletions(-)
> >>>>>
> >>>>> diff --git a/libavformat/avformat.c b/libavformat/avformat.c
> >>>>> index 30d6ea6a49..242187c359 100644
> >>>>> --- a/libavformat/avformat.c
> >>>>> +++ b/libavformat/avformat.c
> >>>>> @@ -235,6 +235,46 @@ int ff_stream_side_data_copy(AVStream *dst, const AVStream *src)
> >>>>> return 0;
> >>>>> }
> >>>>>
> >>>>> +int ff_stream_params_copy(AVStream *dst, const AVStream *src)
> >>>>> +{
> >>>>> + int ret;
> >>>>> +
> >>>>> + dst->id = src->id;
> >>>>> + dst->time_base = src->time_base;
> >>>>> + dst->start_time = src->start_time;
> >>>>> + dst->duration = src->duration;
> >>>>> + dst->nb_frames = src->nb_frames;
> >>>>> + dst->disposition = src->disposition;
> >>>>> + dst->discard = src->discard;
> >>>>> + dst->sample_aspect_ratio = src->sample_aspect_ratio;
> >>>>> + dst->avg_frame_rate = src->avg_frame_rate;
> >>>>> + dst->event_flags = src->event_flags;
> >>>>> + dst->r_frame_rate = src->r_frame_rate;
> >>>>> + dst->pts_wrap_bits = src->pts_wrap_bits;
> >>>>> +
> >>>>> + av_dict_free(&dst->metadata);
> >>>>> + ret = av_dict_copy(&dst->metadata, src->metadata, 0);
> >>>>> + if (ret < 0)
> >>>>> + return ret;
> >>>>> +
> >>>>> + ret = avcodec_parameters_copy(dst->codecpar, src->codecpar);
> >>>>> + if (ret < 0)
> >>>>> + return ret;
> >>>>> +
> >>>>> + ret = ff_stream_side_data_copy(dst, src);
> >>>>> + if (ret < 0)
> >>>>> + return ret;
> >>>>> +
> >>>>> + av_packet_unref(&dst->attached_pic);
> >>>>> + if (src->attached_pic.size > 0) {
> >>>>> + ret = av_packet_ref(&dst->attached_pic, &src->attached_pic);
> >>>>> + if (ret < 0)
> >>>>> + return ret;
> >>>>> + }
> >>>>> +
> >>>>> + return 0;
> >>>>> +}
> >>>>> +
> >>>>> AVProgram *av_new_program(AVFormatContext *ac, int id)
> >>>>> {
> >>>>> AVProgram *program = NULL;
> >>>>> diff --git a/libavformat/fifo.c b/libavformat/fifo.c
> >>>>> index ead2bdc5cf..fef116d040 100644
> >>>>> --- a/libavformat/fifo.c
> >>>>> +++ b/libavformat/fifo.c
> >>>>> @@ -509,7 +509,7 @@ static int fifo_mux_init(AVFormatContext *avf, const AVOutputFormat *oformat,
> >>>>> if (!st)
> >>>>> return AVERROR(ENOMEM);
> >>>>>
> >>>>> - ret = ff_stream_encode_params_copy(st, avf->streams[i]);
> >>>>> + ret = ff_stream_params_copy(st, avf->streams[i]);
> >>>>> if (ret < 0)
> >>>>> return ret;
> >>>>> }
> >>>>> diff --git a/libavformat/internal.h b/libavformat/internal.h
> >>>>> index b6b8fbf56f..87a00bbae3 100644
> >>>>> --- a/libavformat/internal.h
> >>>>> +++ b/libavformat/internal.h
> >>>>> @@ -625,6 +625,18 @@ enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
> >>>>> */
> >>>>> int ff_stream_side_data_copy(AVStream *dst, const AVStream *src);
> >>>>>
> >>>>> +/**
> >>>>> + * Copy all stream parameters from source to destination stream, with the
> >>>>> + * exception of:
> >>>>> + * * the index field, which is usually set by avformat_new_stream()
> >>>>> + * * the attached_pic field, if attached_pic.size is 0 or less
> >>>>> + *
> >>>>> + * @param dst pointer to destination AVStream
> >>>>> + * @param src pointer to source AVStream
> >>>>> + * @return >=0 on success, AVERROR code on error
> >>>>> + */
> >>>>> +int ff_stream_params_copy(AVStream *dst, const AVStream *src);
> >>>>> +
> >>>>> /**
> >>>>> * Wrap ffurl_move() and log if error happens.
> >>>>> *
> >>>>> diff --git a/libavformat/mux.h b/libavformat/mux.h
> >>>>> index c01da82194..1bfcaf795f 100644
> >>>>> --- a/libavformat/mux.h
> >>>>> +++ b/libavformat/mux.h
> >>>>> @@ -113,15 +113,6 @@ int ff_format_shift_data(AVFormatContext *s, int64_t read_start, int shift_size)
> >>>>> */
> >>>>> int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **options);
> >>>>>
> >>>>> -/**
> >>>>> - * Copy encoding parameters from source to destination stream
> >>>>> - *
> >>>>> - * @param dst pointer to destination AVStream
> >>>>> - * @param src pointer to source AVStream
> >>>>> - * @return >=0 on success, AVERROR code on error
> >>>>> - */
> >>>>> -int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src);
> >>>>> -
> >>>>> /**
> >>>>> * Parse creation_time in AVFormatContext metadata if exists and warn if the
> >>>>> * parsing fails.
> >>>>> diff --git a/libavformat/mux_utils.c b/libavformat/mux_utils.c
> >>>>> index eb8ea3d560..2fa2ab5b0f 100644
> >>>>> --- a/libavformat/mux_utils.c
> >>>>> +++ b/libavformat/mux_utils.c
> >>>>> @@ -121,34 +121,6 @@ int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **op
> >>>>> return 0;
> >>>>> }
> >>>>>
> >>>>> -int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src)
> >>>>> -{
> >>>>> - int ret;
> >>>>> -
> >>>>> - dst->id = src->id;
> >>>>> - dst->time_base = src->time_base;
> >>>>> - dst->nb_frames = src->nb_frames;
> >>>>> - dst->disposition = src->disposition;
> >>>>> - dst->sample_aspect_ratio = src->sample_aspect_ratio;
> >>>>> - dst->avg_frame_rate = src->avg_frame_rate;
> >>>>> - dst->r_frame_rate = src->r_frame_rate;
> >>>>> -
> >>>>> - av_dict_free(&dst->metadata);
> >>>>> - ret = av_dict_copy(&dst->metadata, src->metadata, 0);
> >>>>> - if (ret < 0)
> >>>>> - return ret;
> >>>>> -
> >>>>> - ret = avcodec_parameters_copy(dst->codecpar, src->codecpar);
> >>>>> - if (ret < 0)
> >>>>> - return ret;
> >>>>> -
> >>>>> - ret = ff_stream_side_data_copy(dst, src);
> >>>>> - if (ret < 0)
> >>>>> - return ret;
> >>>>> -
> >>>>> - return 0;
> >>>>> -}
> >>>>> -
> >>>>> int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds)
> >>>>> {
> >>>>> AVDictionaryEntry *entry;
> >>>>> diff --git a/libavformat/segment.c b/libavformat/segment.c
> >>>>> index fa435d9f32..a8f3e94714 100644
> >>>>> --- a/libavformat/segment.c
> >>>>> +++ b/libavformat/segment.c
> >>>>> @@ -169,7 +169,7 @@ static int segment_mux_init(AVFormatContext *s)
> >>>>>
> >>>>> if (!(st = avformat_new_stream(oc, NULL)))
> >>>>> return AVERROR(ENOMEM);
> >>>>> - ret = ff_stream_encode_params_copy(st, ist);
> >>>>> + ret = ff_stream_params_copy(st, ist);
> >>>>> if (ret < 0)
> >>>>> return ret;
> >>>>> opar = st->codecpar;
> >>>>> diff --git a/libavformat/tee.c b/libavformat/tee.c
> >>>>> index f1f2a9d2a5..dbfad604d0 100644
> >>>>> --- a/libavformat/tee.c
> >>>>> +++ b/libavformat/tee.c
> >>>>> @@ -289,7 +289,7 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
> >>>>> goto end;
> >>>>> }
> >>>>>
> >>>>> - ret = ff_stream_encode_params_copy(st2, st);
> >>>>> + ret = ff_stream_params_copy(st2, st);
> >>>>> if (ret < 0)
> >>>>> goto end;
> >>>>> }
> >>>>> diff --git a/libavformat/webm_chunk.c b/libavformat/webm_chunk.c
> >>>>> index d69db3a004..39f21fce7a 100644
> >>>>> --- a/libavformat/webm_chunk.c
> >>>>> +++ b/libavformat/webm_chunk.c
> >>>>> @@ -94,7 +94,7 @@ static int webm_chunk_init(AVFormatContext *s)
> >>>>> if (!(st = avformat_new_stream(oc, NULL)))
> >>>>> return AVERROR(ENOMEM);
> >>>>>
> >>>>> - if ((ret = ff_stream_encode_params_copy(st, ost)) < 0)
> >>>>> + if ((ret = ff_stream_params_copy(st, ost)) < 0)
> >>>>> return ret;
> >>>>>
> >>>>> if (wc->http_method)
> >>>>
> >>>> Looking at these callers shows that they all have one thing in common:
> >>>> They create a stream and immediately afterwards copy stream parameters.
> >>>> The caller that you intend to add in #2 does the same. How about we make
> >>>> a function that is equivalent to
> >>>> avformat_new_stream+ff_stream_params_copy above and use that? (But
> >>>> please leave ff_stream_params_copy as it is in the form of a static
> >>>> function.)
> >>>
> >>> avformat_clone_stream()?
> >>>
> >>
> >> I was not thinking about a public function. But clone_stream sounds good.
> >
> > Something like this?
> >
> > int ff_stream_clone(AVFormatContext *s, AVStream **dst, const AVStream *src)
> > {
> > AVStream *st;
> > int ret;
> >
> > st = avformat_new_stream(s, NULL);
> > if (!st)
> > return AVERROR(ENOMEM);
> >
> > ret = stream_params_copy(st, src);
> > if (ret < 0)
> > return ret;
> >
> > *dst = st;
> >
> > return 0;
> > }
> >
>
> I'd use AVStream *ff_stream_clone(AVFormatContext *dst_ctx, const
> AVStream *src);
How does one recover a pointer to the stream that was just created?
Isn't there a potential race condition with dst_ctx[nb_streams - 1]?
>
> - Andreas
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