[FFmpeg-devel] [PATCH 05/13] lavc/av1*: fix exporting framerate
James Almer
jamrial at gmail.com
Wed May 10 14:52:34 EEST 2023
On 5/7/2023 10:32 AM, Anton Khirnov wrote:
> * take num_ticks_per_picture_minus_1 into account, since that is a part
> of the framerate computation
> * stop exporting num_ticks_per_picture_minus_1 into
> AVCodecContext.ticks_per_frame, as that field is used for other
> purposes (in conjunction with repeat_pict, which is not used at all by
> av1)
> ---
> libavcodec/Makefile | 2 +-
> libavcodec/av1_parse.c | 15 +++++++++++++++
> libavcodec/av1_parse.h | 4 ++++
> libavcodec/av1_parser.c | 9 ++++-----
> libavcodec/av1dec.c | 12 +++---------
> 5 files changed, 27 insertions(+), 15 deletions(-)
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index b0971ce833..8162bcf4fa 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -1143,7 +1143,7 @@ OBJS-$(CONFIG_AC3_PARSER) += aac_ac3_parser.o ac3tab.o \
> ac3_channel_layout_tab.o
> OBJS-$(CONFIG_ADX_PARSER) += adx_parser.o
> OBJS-$(CONFIG_AMR_PARSER) += amr_parser.o
> -OBJS-$(CONFIG_AV1_PARSER) += av1_parser.o
> +OBJS-$(CONFIG_AV1_PARSER) += av1_parser.o av1_parse.o
> OBJS-$(CONFIG_AVS2_PARSER) += avs2.o avs2_parser.o
> OBJS-$(CONFIG_AVS3_PARSER) += avs3_parser.o
> OBJS-$(CONFIG_BMP_PARSER) += bmp_parser.o
> diff --git a/libavcodec/av1_parse.c b/libavcodec/av1_parse.c
> index 59ea0bc6e7..cf325e09b9 100644
> --- a/libavcodec/av1_parse.c
> +++ b/libavcodec/av1_parse.c
> @@ -24,6 +24,7 @@
>
> #include "av1.h"
> #include "av1_parse.h"
> +#include "cbs_av1.h"
> #include "bytestream.h"
>
> int ff_av1_extract_obu(AV1OBU *obu, const uint8_t *buf, int length, void *logctx)
> @@ -108,3 +109,17 @@ void ff_av1_packet_uninit(AV1Packet *pkt)
> av_freep(&pkt->obus);
> pkt->obus_allocated = pkt->obus_allocated_size = 0;
> }
> +
> +AVRational ff_av1_framerate(const AV1RawTimingInfo *ti)
Could i ask you to instead pass num_units_in_display_tick, time_scale
and num_ticks_per_picture as arguments to this function, instead of
including cbs_av1 in av1_parse? I devised that module as a lightweight
and reduced alternative to the full bitstream parser that's CBS, used by
the extract_extradata bsf and even included by the av1 demuxer (for the
couple inlined functions in the header).
It should also let you reuse it in libdav1d.c, afaict.
> +{
> + const int ticks = ti->num_ticks_per_picture_minus_1 + 1;
> + AVRational fr = (AVRational){ 0, 1 };
> +
> + if (ti->num_units_in_display_tick && ti->time_scale &&
> + ticks < INT_MAX / ti->num_units_in_display_tick) {
> + av_reduce(&fr.den, &fr.num, ti->num_units_in_display_tick * ticks,
> + ti->time_scale, INT_MAX);
> + }
> +
> + return fr;
> +}
> diff --git a/libavcodec/av1_parse.h b/libavcodec/av1_parse.h
> index f4a5d2830e..60a6fd0ba2 100644
> --- a/libavcodec/av1_parse.h
> +++ b/libavcodec/av1_parse.h
> @@ -181,4 +181,8 @@ static inline int get_obu_bit_length(const uint8_t *buf, int size, int type)
> return size;
> }
>
> +struct AV1RawTimingInfo;
> +
> +AVRational ff_av1_framerate(const struct AV1RawTimingInfo *ti);
> +
> #endif /* AVCODEC_AV1_PARSE_H */
> diff --git a/libavcodec/av1_parser.c b/libavcodec/av1_parser.c
> index 14dae92fe9..978bbebe30 100644
> --- a/libavcodec/av1_parser.c
> +++ b/libavcodec/av1_parser.c
> @@ -21,6 +21,8 @@
> */
>
> #include "libavutil/avassert.h"
> +
> +#include "av1_parse.h"
> #include "cbs.h"
> #include "cbs_av1.h"
> #include "parser.h"
> @@ -162,11 +164,8 @@ static int av1_parser_parse(AVCodecParserContext *ctx,
> avctx->color_trc = (enum AVColorTransferCharacteristic) color->transfer_characteristics;
> avctx->color_range = color->color_range ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
>
> - if (seq->timing_info_present_flag) {
> - const AV1RawTimingInfo *timing = &seq->timing_info;
> - av_reduce(&avctx->framerate.den, &avctx->framerate.num,
> - timing->num_units_in_display_tick, timing->time_scale, INT_MAX);
> - }
> + if (seq->timing_info_present_flag)
> + avctx->framerate = ff_av1_framerate(&seq->timing_info);
>
> end:
> ff_cbs_fragment_reset(td);
> diff --git a/libavcodec/av1dec.c b/libavcodec/av1dec.c
> index c90c9c1a69..693673b436 100644
> --- a/libavcodec/av1dec.c
> +++ b/libavcodec/av1dec.c
> @@ -26,6 +26,7 @@
> #include "libavutil/pixdesc.h"
> #include "libavutil/opt.h"
> #include "avcodec.h"
> +#include "av1_parse.h"
> #include "av1dec.h"
> #include "atsc_a53.h"
> #include "bytestream.h"
> @@ -709,15 +710,8 @@ static int set_context_with_sequence(AVCodecContext *avctx,
> }
> avctx->sample_aspect_ratio = (AVRational) { 1, 1 };
>
> - if (seq->timing_info.num_units_in_display_tick &&
> - seq->timing_info.time_scale) {
> - av_reduce(&avctx->framerate.den, &avctx->framerate.num,
> - seq->timing_info.num_units_in_display_tick,
> - seq->timing_info.time_scale,
> - INT_MAX);
> - if (seq->timing_info.equal_picture_interval)
> - avctx->ticks_per_frame = seq->timing_info.num_ticks_per_picture_minus_1 + 1;
> - }
> + if (seq->timing_info_present_flag)
> + avctx->framerate = ff_av1_framerate(&seq->timing_info);
>
> return 0;
> }
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