Hi Marton,
Il 2021-05-12 19:18 Marton Balint ha scritto:
On Wed, 12 May 2021, Ubaldo Porcheddu wrote:
Hi Marton,
+ }
+
+ //private data
+ desc_len += 6 + 2;
+ *q++ = 0x5F;
+ *q++ = 4;
+ *q++ = 0x00;
+ *q++ = 0x00;
+ put16(&q, 40);
What are these?
I didn't find any official document about it but this seems to be the
way many national (FR,IT,UK) broadcasters are writing the virtual
channel private data header and the one recognized by many popular tv
on the market.
But this looks like a separate descriptor from the virtual channels
(logical_channel_descriptor).
I think it is better to remove it until it is more clear what it does,
or maybe we add an extra mpegts flag like "nit_lcn_extra" ?
logical_channel_descriptor() is documented for example here:
https://forums.mediaspy.org/uploads/short-url/2wA2rGhOkh2yjlbcWMtcQizBv8L.pdf
So you should use the terminology that is used in the document above.
Ok, rewritten accordly.
+ ts->nit_period = av_rescale(ts->nit_period_us, PCR_TIME_BASE,
AV_TIME_BASE);
if (ts->mux_rate == 1)
av_log(s, AV_LOG_VERBOSE, "muxrate VBR, ");
@@ -1154,12 +1237,14 @@ static int mpegts_init(AVFormatContext *s)
"sdt every %"PRId64" ms, pat/pmt every %"PRId64" ms\n",
av_rescale(ts->sdt_period, 1000, PCR_TIME_BASE),
av_rescale(ts->pat_period, 1000, PCR_TIME_BASE));
+ if (ts->nit_enable > 0)
+ av_log(s, AV_LOG_VERBOSE, "nit every %"PRId64" ms\n",
av_rescale(ts->nit_period, 1000, PCR_TIME_BASE));
Maybe you should continue the last log line which already describes
the
interval of various tables, and not start a new line.
The idea is to have the NIT emission optional so I don't know if is a
good idea to stat its periodical transmission on the same line, when
disabled?
I meant something like:
av_log(s, AV_LOG_VERBOSE,
"sdt every %"PRId64" ms, pat/pmt every %"PRId64" ms",
av_rescale(ts->sdt_period, 1000, PCR_TIME_BASE),
av_rescale(ts->pat_period, 1000, PCR_TIME_BASE));
if (nit_enabled)
av_log(s, AV_LOG_VERBOSE, ", nit every %"PRId64" ms")
av_log(s, AV_LOG_VERBOSE, "\n")
Ok, clear now :)
Also docs/muxers.texi update is missing for the new feature.
is there any guide on what an how to add it? :)
No guide, but should be straightforward based on the existing
documentation of the mpegts muxer.
You mean something like this (I am changing "nit_enable" option with
"nit_emit" flag):
--- ffmpeg.old/doc/muxers.texi 2021-05-09 18:20:04.000000000 +0200
+++ ffmpeg.new/doc/muxers.texi 2021-05-12 16:52:38.368198223 +0200
@@ -1876,6 +1876,8 @@
Conform to System B (DVB) instead of System A (ATSC).
@item initial_discontinuity
Mark the initial packet of each stream as discontinuity.
+@item nit_emit
+Emit NIT table.
@end table
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
