[FFmpeg-devel] [PATCH 1/2] avformat/nutenc: fix duration estimation by writing EOR packets
James Almer
jamrial at gmail.com
Wed Dec 19 22:53:17 EET 2018
On 12/18/2018 10:56 AM, Paul B Mahol wrote:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
> libavformat/nut.h | 3 +
> libavformat/nutenc.c | 130 +++++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 129 insertions(+), 4 deletions(-)
>
> diff --git a/libavformat/nut.h b/libavformat/nut.h
> index a4409ee23d..4b15dca1ea 100644
> --- a/libavformat/nut.h
> +++ b/libavformat/nut.h
> @@ -76,6 +76,9 @@ typedef struct StreamContext {
> int last_flags;
> int skip_until_key_frame;
> int64_t last_pts;
> + int64_t eor_pts;
> + int64_t eor_dts;
> + int eor_flushed;
> int time_base_id;
> AVRational *time_base;
> int msb_pts_shift;
> diff --git a/libavformat/nutenc.c b/libavformat/nutenc.c
> index e9a3bb49db..9d1c540a9d 100644
> --- a/libavformat/nutenc.c
> +++ b/libavformat/nutenc.c
> @@ -940,6 +940,80 @@ fail:
> return ret;
> }
>
> +static void nut_update_max_pts(AVFormatContext *s, int stream_index, int64_t pts)
> +{
> + NUTContext *nut = s->priv_data;
> + StreamContext *nus = &nut->stream[stream_index];
> +
> + if (!nut->max_pts_tb || av_compare_ts(nut->max_pts, *nut->max_pts_tb, pts, *nus->time_base) < 0) {
> + nut->max_pts = pts;
> + nut->max_pts_tb = nus->time_base;
> + }
> +}
> +
> +static int nut_write_eor(AVFormatContext *s, AVPacket *pkt)
> +{
> + AVIOContext *bc = s->pb, *dyn_bc;
> + NUTContext *nut = s->priv_data;
> + StreamContext *nus = &nut->stream[pkt->stream_index];
> + int ret, frame_code, flags, needed_flags;
> + int64_t pts = pkt->pts;
> + int64_t coded_pts;
> + FrameCode *fc;
> +
> + coded_pts = pts & ((1 << nus->msb_pts_shift) - 1);
> + if (ff_lsb2full(nus, coded_pts) != pts)
> + coded_pts = pts + (1 << nus->msb_pts_shift);
> +
> + nut->last_syncpoint_pos = avio_tell(bc);
> + ret = avio_open_dyn_buf(&dyn_bc);
> + if (ret < 0)
> + return ret;
> + put_tt(nut, nus->time_base, dyn_bc, pkt->dts);
> + ff_put_v(dyn_bc, 0);
> +
> + if (nut->flags & NUT_BROADCAST) {
> + put_tt(nut, nus->time_base, dyn_bc,
> + av_rescale_q(av_gettime(), AV_TIME_BASE_Q, *nus->time_base));
> + }
> + put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
> +
> + frame_code = -1;
> + for (int i = 0; i < 256; i++) {
> + FrameCode *fc = &nut->frame_code[i];
> + int flags = fc->flags;
> +
> + if (flags & FLAG_INVALID)
> + continue;
> +
> + if (!(flags & FLAG_CODED)) {
> + continue;
> + }
> +
> + frame_code = i;
> + break;
> + }
> + av_assert0(frame_code != -1);
> +
> + fc = &nut->frame_code[frame_code];
> + flags = fc->flags;
> + needed_flags = FLAG_KEY | FLAG_EOR | FLAG_CODED_PTS | FLAG_STREAM_ID;
> +
> + ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
> + avio_w8(bc, frame_code);
> + if (flags & FLAG_CODED) {
> + ff_put_v(bc, (flags ^ needed_flags) & ~(FLAG_CODED));
> + flags = needed_flags;
> + }
> + if (flags & FLAG_STREAM_ID) ff_put_v(bc, pkt->stream_index);
> + if (flags & FLAG_CODED_PTS) ff_put_v(bc, coded_pts);
> + ffio_get_checksum(bc);
> +
> + nut_update_max_pts(s, pkt->stream_index, pkt->pts);
> +
> + return 0;
> +}
> +
> static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
> {
> NUTContext *nut = s->priv_data;
> @@ -956,6 +1030,9 @@ static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
> int data_size = pkt->size;
> uint8_t *sm_buf = NULL;
>
> + if (!data_size)
> + return nut_write_eor(s, pkt);
> +
> if (pkt->pts < 0) {
> av_log(s, AV_LOG_ERROR,
> "Negative pts not supported stream %d, pts %"PRId64"\n",
> @@ -1150,10 +1227,7 @@ static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
> nus->keyframe_pts[nut->sp_count] = pkt->pts;
> }
>
> - if (!nut->max_pts_tb || av_compare_ts(nut->max_pts, *nut->max_pts_tb, pkt->pts, *nus->time_base) < 0) {
> - nut->max_pts = pkt->pts;
> - nut->max_pts_tb = nus->time_base;
> - }
> + nut_update_max_pts(s, pkt->stream_index, pkt->pts);
>
> fail:
> av_freep(&sm_buf);
> @@ -1161,6 +1235,53 @@ fail:
> return ret;
> }
>
> +static int nut_interleave_packet(AVFormatContext *s, AVPacket *out,
> + AVPacket *pkt, int flush)
> +{
> + NUTContext *nut = s->priv_data;
> + int ret;
> +
> + if (pkt) {
> + StreamContext *nus = &nut->stream[pkt->stream_index];
> +
> + nus->eor_pts = FFMAX(pkt->pts + pkt->duration, nus->eor_pts);
> + nus->eor_dts = FFMAX(pkt->dts + pkt->duration, nus->eor_dts);
> + } else if (flush) {
> + StreamContext *nus;
> + int i;
> +
> + for (i = 0; i < s->nb_streams; i++) {
> + nus = &nut->stream[i];
> +
> + if (nus->eor_flushed)
> + continue;
> +
> + if (s->streams[i]->last_in_packet_buffer)
> + continue;
> +
> + break;
> + }
> +
> + if (i < s->nb_streams) {
> + pkt = av_packet_alloc();
> + if (!pkt)
> + return AVERROR(ENOMEM);
> +
> + ret = av_new_packet(pkt, 0);
> + if (ret < 0)
> + return ret;
> + pkt->stream_index = i;
> + pkt->pts = nus->eor_pts;
> + pkt->dts = nus->eor_dts;
> + pkt->duration = 0;
> + nus->eor_flushed = 1;
> + ret = ff_interleave_packet_per_dts(s, out, pkt, 0);
This apparently will create a new reference for pkt, but will not unref
the existing one or free the packet.
The line below should be av_packet_free(&pkt) instead.
> + pkt = NULL;
> + }
> + }
> + return ff_interleave_packet_per_dts(s, out, pkt, flush);
> +}
> +
> static int nut_write_trailer(AVFormatContext *s)
> {
> NUTContext *nut = s->priv_data;
> @@ -1225,6 +1346,7 @@ AVOutputFormat ff_nut_muxer = {
> .write_header = nut_write_header,
> .write_packet = nut_write_packet,
> .write_trailer = nut_write_trailer,
> + .interleave_packet = nut_interleave_packet,
> .deinit = nut_write_deinit,
> .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
> .codec_tag = ff_nut_codec_tags,
>
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