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scte35dec: set default segmentation duration (1s)
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@rbouqueau
rbouqueau committed Apr 7, 2024
1 parent ead8914 commit 845b323
Showing 1 changed file with 19 additions and 10 deletions.
29 changes: 19 additions & 10 deletions src/filters/dec_scte35.c
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Expand Up @@ -46,7 +46,7 @@ typedef struct {
u64 last_dispatched_dts;

// used to segment empty boxes
GF_Fraction seg_dur;
GF_Fraction segdur;
u8 emeb_box[8];
Bool seg_setup;
u64 orig_ts;
Expand Down Expand Up @@ -121,7 +121,7 @@ static Bool scte35dec_process_event(GF_Filter *filter, const GF_FilterEvent *evt
if (evt->base.type==GF_FEVT_ENCODE_HINTS) {
SCTE35DecCtx *ctx = gf_filter_get_udta(filter);
if (evt->encode_hints.intra_period.den && evt->encode_hints.intra_period.num) {
ctx->seg_dur = evt->encode_hints.intra_period;
ctx->segdur = evt->encode_hints.intra_period;
}
return GF_TRUE;
}
Expand Down Expand Up @@ -237,7 +237,7 @@ static GF_Err scte35dec_flush(SCTE35DecCtx *ctx, u64 timestamp, u32 dur)
GF_Err e = scte35dec_flush_emib(ctx, timestamp, dur);
if (e) return e;

if ((ctx->seg_dur.den && ctx->seg_dur.num>0) && ctx->clock < timestamp + dur ) {
if ((ctx->segdur.den && ctx->segdur.num>0) && ctx->clock < timestamp + dur ) {
// complete the segment with an empty box
return scte35dec_flush_emeb(ctx, ctx->clock);
} else {
Expand All @@ -247,7 +247,7 @@ static GF_Err scte35dec_flush(SCTE35DecCtx *ctx, u64 timestamp, u32 dur)

static GF_Err scte35dec_dispatch(SCTE35DecCtx *ctx, u64 dts)
{
if ( !(ctx->seg_dur.den && ctx->seg_dur.num>0) ) {
if ( !(ctx->segdur.den && ctx->segdur.num>0) ) {
// unsegmented: dispatch at each frame
gf_assert(gf_list_count(ctx->ordered_events) <= 1);
GF_Err e = scte35dec_flush(ctx, dts, UINT32_MAX);
Expand All @@ -265,14 +265,14 @@ static GF_Err scte35dec_dispatch(SCTE35DecCtx *ctx, u64 dts)
ctx->nb_forced = 0;
} else {
GF_Fraction64 ts_diff = { ctx->clock - ctx->orig_ts, ctx->timescale };
if (ts_diff.num * ctx->seg_dur.den >= (ctx->nb_forced+1) * ctx->seg_dur.num * ts_diff.den) {
if (ts_diff.num * ctx->segdur.den >= (ctx->nb_forced+1) * ctx->segdur.num * ts_diff.den) {
GF_LOG(GF_LOG_INFO, GF_LOG_CODEC, ("[Scte35Dec] New segment at DTS %d/%u (%lf). Flushing the previous one.\n", ctx->clock, ctx->timescale, (double)ctx->clock/ctx->timescale));
u64 dts = ctx->orig_ts + ctx->nb_forced * ctx->seg_dur.num * ctx->timescale / ctx->seg_dur.den;
u64 dts = ctx->orig_ts + ctx->nb_forced * ctx->segdur.num * ctx->timescale / ctx->segdur.den;
if (dts == ctx->last_dispatched_dts) // first segment
ctx->last_dispatched_dts -= (ctx->seg_dur.num * ctx->timescale / ctx->seg_dur.den);
ctx->last_dispatched_dts -= (ctx->segdur.num * ctx->timescale / ctx->segdur.den);
ctx->nb_forced++;
ctx->clock = dts;
return scte35dec_flush(ctx, dts, ctx->seg_dur.num * ctx->timescale / ctx->seg_dur.den);
return scte35dec_flush(ctx, dts, ctx->segdur.num * ctx->timescale / ctx->segdur.den);
}
}
}
Expand Down Expand Up @@ -381,7 +381,7 @@ GF_Err scte35dec_process(GF_Filter *filter)
ctx->timescale = gf_filter_pck_get_timescale(pck);
ctx->last_dispatched_dts = dts;
ctx->last_pck_dur = gf_filter_pck_get_duration(pck);
} else if (ctx->clock < dts && !(ctx->seg_dur.den && ctx->seg_dur.num>0) &&
} else if (ctx->clock < dts && !(ctx->segdur.den && ctx->segdur.num>0) &&
ctx->last_pck_dur && (ctx->last_pck_dur + ctx->last_dispatched_dts != dts)) {
// drift control
s32 drift = ctx->last_pck_dur + ctx->last_dispatched_dts - dts;
Expand All @@ -406,7 +406,7 @@ GF_Err scte35dec_process(GF_Filter *filter)
// set values according to SCTE 214-3 2015
emib->timescale = gf_filter_pck_get_timescale(pck);
emib->presentation_time_delta = pts - dts;
if (pts < ctx->clock && !(ctx->seg_dur.den && ctx->seg_dur.num>0))
if (pts < ctx->clock && !(ctx->segdur.den && ctx->segdur.num>0))
GF_LOG(GF_LOG_WARNING, GF_LOG_CODEC, ("[Scte35Dec] event overlap detected in immediate dispatch mode (not segmented)\n"));
emib->event_duration = dur;
GF_LOG(GF_LOG_DEBUG, GF_LOG_CODEC, ("[Scte35Dec] detected pts="LLU" (delta="LLU") dur=%u at dts="LLU"\n", pts, pts-dts, dur, dts));
Expand Down Expand Up @@ -441,13 +441,22 @@ static const GF_FilterCapability SCTE35DecCaps[] =
CAP_BOOL(GF_CAPS_OUTPUT_STATIC_EXCLUDED, GF_PROP_PID_UNFRAMED, GF_TRUE),
};

#define OFFS(_n) #_n, offsetof(SCTE35DecCtx, _n)
static const GF_FilterArgs SCTE35DecArgs[] =
{
{ OFFS(segdur), "segmentation duration in seconds. 0/0 flushes immediately for each input packet (beware of the bitrate overhead)", GF_PROP_FRACTION, "1/1", NULL, 0},
{0}
};


GF_FilterRegister SCTE35DecRegister = {
.name = "scte35dec",
GF_FS_SET_DESCRIPTION("SCTE35 decoder")
GF_FS_SET_HELP("This filter extracts SCTE-35 markers attached as properties to audio and video\n"
"packets as 23001-18 'emib' boxes. It also creates empty 'emeb' box in between\n"
"following segmentation as hinted by the graph.")
.private_size = sizeof(SCTE35DecCtx),
.args = SCTE35DecArgs,
.flags = GF_FS_REG_EXPLICIT_ONLY,
SETCAPS(SCTE35DecCaps),
.process = scte35dec_process,
Expand Down

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