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Parse the ASMRuleBook SDP line to dynamically create one new AVStream for
each "rule" described in the ASMRuleBook. Each rule represents a stream of identical content compared to other streams in the same rulebook, but with a possibly different codec/bitrate/etc. See "[PATCH] rdt.c: ASM rulebook parsing and AVStream creation" thread on mailinglist. Originally committed as revision 16466 to svn://svn.ffmpeg.org/ffmpeg/trunk
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@ -76,6 +76,11 @@ ff_rdt_parse_open(AVFormatContext *ic, int first_stream_of_set_idx,
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void
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ff_rdt_parse_close(RDTDemuxContext *s)
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{
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int i;
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for (i = 1; i < s->n_streams; i++)
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s->streams[i]->priv_data = NULL;
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av_free(s);
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}
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@ -423,6 +428,68 @@ rdt_parse_sdp_line (AVFormatContext *s, int st_index,
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return 0;
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}
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static AVStream *
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add_dstream(AVFormatContext *s, AVStream *orig_st)
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{
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AVStream *st;
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if (!(st = av_new_stream(s, 0)))
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return NULL;
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st->codec->codec_type = orig_st->codec->codec_type;
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st->priv_data = orig_st->priv_data;
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st->first_dts = orig_st->first_dts;
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return st;
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}
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static void
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real_parse_asm_rulebook(AVFormatContext *s, AVStream *orig_st,
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const char *p)
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{
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const char *end;
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int n_rules, odd = 0;
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AVStream *st;
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/**
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* The ASMRuleBook contains a list of comma-separated strings per rule,
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* and each rule is separated by a ;. The last one also has a ; at the
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* end so we can use it as delimiter.
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* Every rule occurs twice, once for when the RTSP packet header marker
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* is set and once for if it isn't. We only read the first because we
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* don't care much (that's what the "odd" variable is for).
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* Each rule contains a set of one or more statements, optionally
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* preceeded by a single condition. If there's a condition, the rule
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* starts with a '#'. Multiple conditions are merged between brackets,
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* so there are never multiple conditions spread out over separate
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* statements. Generally, these conditions are bitrate limits (min/max)
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* for multi-bitrate streams.
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*/
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if (*p == '\"') p++;
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for (n_rules = 0; s->nb_streams < MAX_STREAMS;) {
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if (!(end = strchr(p, ';')))
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break;
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if (!odd && end != p) {
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if (n_rules > 0)
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st = add_dstream(s, orig_st);
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else
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st = orig_st;
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n_rules++;
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}
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p = end + 1;
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odd ^= 1;
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}
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}
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void
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ff_real_parse_sdp_a_line (AVFormatContext *s, int stream_index,
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const char *line)
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{
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const char *p = line;
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if (av_strstart(p, "ASMRuleBook:string;", &p))
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real_parse_asm_rulebook(s, s->streams[stream_index], p);
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}
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static PayloadContext *
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rdt_new_extradata (void)
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{
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@ -101,4 +101,15 @@ int ff_rdt_parse_header(const uint8_t *buf, int len,
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int ff_rdt_parse_packet(RDTDemuxContext *s, AVPacket *pkt,
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const uint8_t *buf, int len);
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/**
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* Parse a server-related SDP line.
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*
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* @param s the RTSP AVFormatContext
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* @param stream_index the index of the first stream in the set represented
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* by the SDP m= line (in s->streams)
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* @param buf the SDP line
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*/
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void ff_real_parse_sdp_a_line(AVFormatContext *s, int stream_index,
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const char *buf);
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#endif /* AVFORMAT_RDT_H */
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@ -549,6 +549,9 @@ static void sdp_parse_line(AVFormatContext *s, SDPParseState *s1,
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if (atoi(p) == 1)
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rt->transport = RTSP_TRANSPORT_RDT;
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} else if (s->nb_streams > 0) {
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if (rt->server_type == RTSP_SERVER_REAL)
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ff_real_parse_sdp_a_line(s, s->nb_streams - 1, p);
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rtsp_st = s->streams[s->nb_streams - 1]->priv_data;
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if (rtsp_st->dynamic_handler &&
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rtsp_st->dynamic_handler->parse_sdp_a_line)
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