[FFmpeg-devel] [PATCH 2/7] avformat/dvdvideodec: Implement seeking
Marth64
marth64 at proxyid.net
Sun Jul 28 10:34:40 EEST 2024
Player applications can now enjoy seeking while playing back
a title. Accuracy is at the mercy of what libdvdnav offers,
which is currently dvdnav_jump_to_sector_by_time().
Signed-off-by: Marth64 <marth64 at proxyid.net>
---
libavformat/dvdvideodec.c | 93 ++++++++++++++++++++++++++++++++++-----
1 file changed, 82 insertions(+), 11 deletions(-)
diff --git a/libavformat/dvdvideodec.c b/libavformat/dvdvideodec.c
index e745165e00..e8301b1173 100644
--- a/libavformat/dvdvideodec.c
+++ b/libavformat/dvdvideodec.c
@@ -110,6 +110,7 @@ typedef struct DVDVideoPlaybackState {
int in_pgc; /* if our navigator is in the PGC */
int in_ps; /* if our navigator is in the program stream */
int in_vts; /* if our navigator is in the VTS */
+ int is_seeking; /* relax navigation path while seeking */
int64_t nav_pts; /* PTS according to IFO, not frame-accurate */
uint64_t pgc_duration_est; /* estimated duration as reported by IFO */
uint64_t pgc_elapsed; /* the elapsed time of the PGC, cell-relative */
@@ -722,7 +723,8 @@ static int dvdvideo_play_next_ps_block(AVFormatContext *s, DVDVideoPlaybackState
state->in_pgc = 1;
}
- } else if (state->celln >= e_cell->cellN || state->pgn > cur_pgn) {
+ } else if (!state->is_seeking &&
+ (state->celln >= e_cell->cellN || state->pgn > cur_pgn)) {
return AVERROR_EOF;
}
@@ -735,7 +737,7 @@ static int dvdvideo_play_next_ps_block(AVFormatContext *s, DVDVideoPlaybackState
if (!state->in_pgc)
continue;
- if ((state->ptt > 0 && state->ptt > cur_ptt) ||
+ if ((!state->is_seeking && state->ptt > 0 && state->ptt > cur_ptt) ||
(c->opt_chapter_end > 0 && cur_ptt > c->opt_chapter_end)) {
return AVERROR_EOF;
}
@@ -807,13 +809,15 @@ static int dvdvideo_play_next_ps_block(AVFormatContext *s, DVDVideoPlaybackState
return AVERROR_INPUT_CHANGED;
}
- memcpy(buf, &nav_buf, nav_len);
-
if (state->pgn != cur_pgn)
av_log(s, AV_LOG_WARNING, "Unexpected PG change (expected=%d actual=%d); "
"this could be due to a missed NAV packet\n",
state->pgn, cur_pgn);
+ memcpy(buf, &nav_buf, nav_len);
+
+ state->is_seeking = 0;
+
return nav_len;
case DVDNAV_WAIT:
if (dvdnav_wait_skip(state->dvdnav) != DVDNAV_STATUS_OK) {
@@ -1659,17 +1663,17 @@ static int dvdvideo_read_packet(AVFormatContext *s, AVPacket *pkt)
}
av_log(s, AV_LOG_TRACE, "st=%d pts=%" PRId64 " dts=%" PRId64 " "
- "pts_offset=%" PRId64 " first_pts=%" PRId64 "\n",
+ "pts_offset=%" PRId64 " first_pts=%" PRId64 " is_seeking=%d\n",
pkt->stream_index, pkt->pts, pkt->dts,
- c->pts_offset);
+ c->pts_offset, c->first_pts, c->play_state.is_seeking);
return 0;
discard:
av_log(s, AV_LOG_VERBOSE, "Discarding packet @ st=%d pts=%" PRId64 " dts=%" PRId64 " "
- "st_matched=%d\n",
+ "st_matched=%d is_seeking=%d\n",
st_matched ? pkt->stream_index : -1, pkt->pts, pkt->dts,
- st_matched);
+ st_matched, c->play_state.is_seeking);
return FFERROR_REDO;
}
@@ -1690,6 +1694,72 @@ static int dvdvideo_close(AVFormatContext *s)
return 0;
}
+static int dvdvideo_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+ DVDVideoDemuxContext *c = s->priv_data;
+ int ret;
+ int64_t new_nav_pts;
+ pci_t* new_nav_pci;
+ dsi_t* new_nav_dsi;
+
+ if (c->opt_menu || c->opt_chapter_start > 1) {
+ av_log(s, AV_LOG_ERROR, "Seeking is not compatible with menus or chapter extraction\n");
+
+ return AVERROR_PATCHWELCOME;
+ }
+
+ if ((flags & AVSEEK_FLAG_BYTE))
+ return AVERROR(ENOSYS);
+
+ if (timestamp < 0)
+ return AVERROR(EINVAL);
+
+ if (!c->seek_warned) {
+ av_log(s, AV_LOG_WARNING, "Seeking is inherently unreliable and will result "
+ "in imprecise timecodes from this point\n");
+ c->seek_warned = 1;
+ }
+
+ /* XXX(PATCHWELCOME): use dvdnav_jump_to_sector_by_time(c->play_state.dvdnav, timestamp, 0)
+ * when it is available in a released version of libdvdnav; it is more accurate */
+ if (dvdnav_time_search(c->play_state.dvdnav, timestamp) != DVDNAV_STATUS_OK) {
+ av_log(s, AV_LOG_ERROR, "libdvdnav: seeking to %" PRId64 " failed\n", timestamp);
+
+ return AVERROR_EXTERNAL;
+ }
+
+ new_nav_pts = dvdnav_get_current_time (c->play_state.dvdnav);
+ new_nav_pci = dvdnav_get_current_nav_pci(c->play_state.dvdnav);
+ new_nav_dsi = dvdnav_get_current_nav_dsi(c->play_state.dvdnav);
+
+ if (new_nav_pci == NULL || new_nav_dsi == NULL) {
+ av_log(s, AV_LOG_ERROR, "Invalid NAV packet after seeking\n");
+
+ return AVERROR_INVALIDDATA;
+ }
+
+ c->play_state.in_pgc = 1;
+ c->play_state.in_ps = 0;
+ c->play_state.is_seeking = 1;
+ c->play_state.nav_pts = timestamp;
+ c->play_state.ptm_offset = timestamp;
+ c->play_state.ptm_discont = 0;
+ c->play_state.vobu_e_ptm = new_nav_pci->pci_gi.vobu_s_ptm;
+
+ c->first_pts = 0;
+ c->play_started = 0;
+ c->pts_offset = timestamp;
+ c->subdemux_reset = 0;
+
+ if ((ret = dvdvideo_subdemux_reset(s)) < 0)
+ return ret;
+
+ av_log(s, AV_LOG_DEBUG, "seeking: requested_nav_pts=%" PRId64 " new_nav_pts=%" PRId64 "\n",
+ timestamp, new_nav_pts);
+
+ return 0;
+}
+
#define OFFSET(x) offsetof(DVDVideoDemuxContext, x)
static const AVOption dvdvideo_options[] = {
{"angle", "playback angle number", OFFSET(opt_angle), AV_OPT_TYPE_INT, { .i64=1 }, 1, 9, AV_OPT_FLAG_DECODING_PARAM },
@@ -1718,11 +1788,12 @@ const FFInputFormat ff_dvdvideo_demuxer = {
.p.name = "dvdvideo",
.p.long_name = NULL_IF_CONFIG_SMALL("DVD-Video"),
.p.priv_class = &dvdvideo_class,
- .p.flags = AVFMT_NOFILE | AVFMT_SHOW_IDS | AVFMT_TS_DISCONT |
- AVFMT_NO_BYTE_SEEK | AVFMT_NOGENSEARCH | AVFMT_NOBINSEARCH,
+ .p.flags = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT | AVFMT_SEEK_TO_PTS |
+ AVFMT_NOFILE | AVFMT_NO_BYTE_SEEK | AVFMT_NOGENSEARCH | AVFMT_NOBINSEARCH,
.priv_data_size = sizeof(DVDVideoDemuxContext),
.flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
.read_close = dvdvideo_close,
.read_header = dvdvideo_read_header,
- .read_packet = dvdvideo_read_packet
+ .read_packet = dvdvideo_read_packet,
+ .read_seek = dvdvideo_read_seek
};
--
2.34.1
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