[FFmpeg-devel] [PATCH] DVB EPG decoder
Marton Balint
cus at passwd.hu
Wed Sep 4 00:39:00 EEST 2019
Hi,
I am not sure if you are interested getting only patch 1, 2 and 3
merged, but if you are, then here are my comments for patch 3.
> From 025ec8e8d607d02f2e5b4021783ab8f3b42d0bc1 Mon Sep 17 00:00:00 2001
> From: Anthony Delannoy <anthony.2lannoy at gmail.com>
> Date: Wed, 21 Aug 2019 11:46:56 +0200
> Subject: [PATCH 03/10] lavf/mpegts: EPG extraction from mpegts
>
> ---
> libavformat/mpegts.c | 67 ++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 65 insertions(+), 2 deletions(-)
>
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> index 47d8d5f877..03c1753ac7 100644
> --- a/libavformat/mpegts.c
> +++ b/libavformat/mpegts.c
> @@ -2489,13 +2489,57 @@ static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
> }
> }
>
> +static void eit_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
> +{
> + MpegTSContext *ts = filter->u.section_filter.opaque;
> + MpegTSSectionFilter *tssf = &filter->u.section_filter;
> + const uint8_t *p, *p_end;
> + SectionHeader h1, *h = &h1;
> + int idx;
> + AVProgram *prg;
Maybe you can check if AVStream->discard == DISCARD_ALL for the EIT stream and
skip the packet if the stream is discarded.
> +
> + p_end = section + section_len - 4;
> + p = section;
> +
> + if (parse_section_header(h, &p, p_end) < 0)
> + return;
> + if (h->tid < EIT_TID || h->tid > OEITS_END_TID)
> + return;
> + if (ts->skip_changes)
> + return;
> + if (skip_identical(h, tssf))
> + return;
I don't think these last two checks (skip changes and skip identical) makes
much sense here, just remove them.
> +
> + idx = ff_find_stream_index(ts->stream, filter->pid);
> + if (idx < 0)
> + return;
Instead of finding the stream each time, you should simply add an AVStream
*epg_stream to MpegTsContext, set it where you create the stream, and use that
always.
> +
> + /**
> + * In case we receive an EPG packet before mpegts context is fully
> + * initialized.
> + */
> + if (!ts->pkt)
> + return;
> +
> + new_data_packet(section, section_len, ts->pkt);
> + ts->pkt->stream_index = idx;
> + prg = av_find_program_from_stream(ts->stream, NULL, idx);
> + if (prg && prg->pcr_pid != -1 && prg->discard != AVDISCARD_ALL) {
> + MpegTSFilter *f = ts->pids[prg->pcr_pid];
> + if (f && f->last_pcr != -1)
> + ts->pkt->pts = ts->pkt->dts = f->last_pcr/300;
> + }
This program based logic is no longer needed since EIT is not added to programs.
> + ts->stop_parse = 1;
> +}
> +
> static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
> {
> MpegTSContext *ts = filter->u.section_filter.opaque;
> MpegTSSectionFilter *tssf = &filter->u.section_filter;
> SectionHeader h1, *h = &h1;
> const uint8_t *p, *p_end, *desc_list_end, *desc_end;
> - int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type;
> + int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type,
> + eit_sched, eit_pres_following;
> char *name, *provider_name;
>
> av_log(ts->stream, AV_LOG_TRACE, "SDT:\n");
> @@ -2525,6 +2569,24 @@ static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
> val = get8(&p, p_end);
> if (val < 0)
> break;
> + eit_sched = (val >> 1) & 0x1;
> + eit_pres_following = val & 0x1;
> +
> + if (eit_sched | eit_pres_following) {
> + int idx = ff_find_stream_index(ts->stream, EIT_PID);
> + AVStream *st = (idx >= 0) ? ts->stream->streams[EIT_PID] : NULL;
I guess ts->stream->streams[EIT_PID] wanted to be ts->stream->streams[idx] but
it does not matter because you should rework this if you add epg_stream to
MpegTsContext.
> +
> + if (!st) {
> + st = avformat_new_stream(ts->stream, NULL);
> + if (!st)
> + return;
> + st->id = EIT_PID;
> + st->program_num = sid;
> + st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
> + st->codecpar->codec_id = AV_CODEC_ID_EPG;
> + }
> + }
> +
> desc_list_len = get16(&p, p_end);
> if (desc_list_len < 0)
> break;
> @@ -2975,8 +3037,8 @@ static int mpegts_read_header(AVFormatContext *s)
> seek_back(s, pb, pos);
>
> mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1);
> -
> mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1);
> + mpegts_open_section_filter(ts, EIT_PID, eit_cb, ts, 1);
>
> handle_packets(ts, probesize / ts->raw_packet_size);
> /* if could not find service, enable auto_guess */
> @@ -3233,6 +3295,7 @@ MpegTSContext *avpriv_mpegts_parse_open(AVFormatContext *s)
> ts->auto_guess = 1;
> mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1);
> mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1);
> + mpegts_open_section_filter(ts, EIT_PID, eit_cb, ts, 1);
>
> return ts;
> }
> --
> 2.23.0
Regards,
Marton
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