[FFmpeg-devel] [PATCH 1/2] lavf: stop honoring AVFMT_FLAG_AUTO_BSF

[Gyan Doshi]

On 2022-11-25 11:30 pm, Anton Khirnov wrote:
> There should no longer be reason for the callers to disable this.
> In-muxer bitstream filtering should be considered a part of the muxer
> internals and invisible to the caller.
> ---
>   libavformat/internal.h      | 5 +++++
>   libavformat/movenc.c        | 5 +++--
>   libavformat/mux.c           | 3 ++-
>   libavformat/options_table.h | 2 +-
>   4 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/libavformat/internal.h b/libavformat/internal.h
> index ce837fefc76..e96bf4cc56d 100644
> --- a/libavformat/internal.h
> +++ b/libavformat/internal.h
> @@ -186,6 +186,11 @@ typedef struct FFFormatContext {
>        * Contexts and child contexts do not contain a metadata option
>        */
>       int metafree;
> +
> +    /**
> +     * Disable muxer-level bitstream filtering.
> +     */
> +    int disable_bsf;
>   } FFFormatContext;
>   
>   static av_always_inline FFFormatContext *ffformatcontext(AVFormatContext *s)
> diff --git a/libavformat/movenc.c b/libavformat/movenc.c
> index 064b5419721..a4dd8619dcc 100644
> --- a/libavformat/movenc.c
> +++ b/libavformat/movenc.c
> @@ -6829,6 +6829,7 @@ static int mov_create_dvd_sub_decoder_specific_info(MOVTrack *track,
>   
>   static int mov_init(AVFormatContext *s)
>   {
> +    FFFormatContext *const si = ffformatcontext(s);
>       MOVMuxContext *mov = s->priv_data;
>       int i, ret;
>   
> @@ -6875,9 +6876,9 @@ static int mov_init(AVFormatContext *s)
>           mov->flags |= FF_MOV_FLAG_FRAGMENT | FF_MOV_FLAG_EMPTY_MOOV |
>                         FF_MOV_FLAG_DEFAULT_BASE_MOOF | FF_MOV_FLAG_NEGATIVE_CTS_OFFSETS;
>   
> -    if (mov->flags & FF_MOV_FLAG_EMPTY_MOOV && s->flags & AVFMT_FLAG_AUTO_BSF) {
> +    if (mov->flags & FF_MOV_FLAG_EMPTY_MOOV) {
>           av_log(s, AV_LOG_VERBOSE, "Empty MOOV enabled; disabling automatic bitstream filtering\n");
> -        s->flags &= ~AVFMT_FLAG_AUTO_BSF;
> +        si->disable_bsf = 1;
>       }
>   
>       if (mov->flags & FF_MOV_FLAG_GLOBAL_SIDX && mov->flags & FF_MOV_FLAG_SKIP_SIDX) {
> diff --git a/libavformat/mux.c b/libavformat/mux.c
> index 37fe19358de..fff500dd554 100644
> --- a/libavformat/mux.c
> +++ b/libavformat/mux.c
> @@ -1072,9 +1072,10 @@ const AVPacket *ff_interleaved_peek(AVFormatContext *s, int stream)
>   
>   static int check_bitstream(AVFormatContext *s, FFStream *sti, AVPacket *pkt)
>   {
> +    FFFormatContext *const si = ffformatcontext(s);
>       int ret;
>   
> -    if (!(s->flags & AVFMT_FLAG_AUTO_BSF))
> +    if (si->disable_bsf)
>           return 1;
>   
>       if (s->oformat->check_bitstream) {
> diff --git a/libavformat/options_table.h b/libavformat/options_table.h
> index 86d836cfebb..83e6c6fb3cb 100644
> --- a/libavformat/options_table.h
> +++ b/libavformat/options_table.h
> @@ -39,7 +39,7 @@ static const AVOption avformat_options[] = {
>   {"probesize", "set probing size", OFFSET(probesize), AV_OPT_TYPE_INT64, {.i64 = 5000000 }, 32, INT64_MAX, D},
>   {"formatprobesize", "number of bytes to probe file format", OFFSET(format_probesize), AV_OPT_TYPE_INT, {.i64 = PROBE_BUF_MAX}, 0, INT_MAX-1, D},
>   {"packetsize", "set packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, 0, INT_MAX, E},
> -{"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_AUTO_BSF }, INT_MIN, INT_MAX, D|E, "fflags"},
> +{"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0 }, INT_MIN, INT_MAX, D|E, "fflags"},
>   {"flush_packets", "reduce the latency by flushing out packets immediately", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FLUSH_PACKETS }, INT_MIN, INT_MAX, E, "fflags"},
>   {"ignidx", "ignore index", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_IGNIDX }, INT_MIN, INT_MAX, D, "fflags"},
>   {"genpts", "generate pts", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_GENPTS }, INT_MIN, INT_MAX, D, "fflags"},

The flag is set in hlsenc and segment.c.  Does the original rationale no 
longer apply?

Regards,
Gyan