mirror of
https://git.ffmpeg.org/ffmpeg.git
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mpeg TS demux API (called from RTP layer) - raw mpeg TS reader (uses fake codec MPEG2TS)
Originally committed as revision 2446 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Fabrice Bellard
parent
985180a1b8
commit
b45a7a18d3
@ -29,7 +29,7 @@
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synchronisation is lost */
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#define MAX_RESYNC_SIZE 4096
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static int add_pes_stream(AVFormatContext *s, int pid);
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static int add_pes_stream(MpegTSContext *ts, int pid);
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enum MpegTSFilterType {
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MPEGTS_PES,
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@ -74,13 +74,20 @@ typedef struct MpegTSService {
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char *name;
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} MpegTSService;
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typedef struct MpegTSContext {
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struct MpegTSContext {
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/* user data */
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AVFormatContext *stream;
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int raw_packet_size; /* raw packet size, including FEC if present */
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int auto_guess; /* if true, all pids are analized to find streams */
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int set_service_ret;
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int mpeg2ts_raw; /* force raw MPEG2 transport stream output, if possible */
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int mpeg2ts_compute_pcr; /* compute exact PCR for each transport stream packet */
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/* used to estimate the exact PCR */
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int64_t cur_pcr;
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int pcr_incr;
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/* data needed to handle file based ts */
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int stop_parse; /* stop parsing loop */
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AVPacket *pkt; /* packet containing av data */
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@ -100,7 +107,7 @@ typedef struct MpegTSContext {
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int req_sid;
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MpegTSFilter *pids[NB_PID_MAX];
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} MpegTSContext;
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};
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static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1,
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const uint8_t *buf, int buf_size, int is_start)
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@ -151,7 +158,10 @@ MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid,
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{
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MpegTSFilter *filter;
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MpegTSSectionFilter *sec;
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#ifdef DEBUG_SI
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printf("Filter: pid=0x%x\n", pid);
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#endif
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if (pid >= NB_PID_MAX || ts->pids[pid])
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return NULL;
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filter = av_mallocz(sizeof(MpegTSFilter));
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@ -391,7 +401,7 @@ static void pmt_cb(void *opaque, const uint8_t *section, int section_len)
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case STREAM_TYPE_VIDEO_MPEG1:
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case STREAM_TYPE_VIDEO_MPEG2:
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case STREAM_TYPE_AUDIO_AC3:
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add_pes_stream(ts->stream, pid);
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add_pes_stream(ts, pid);
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break;
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default:
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/* we ignore the other streams */
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@ -619,6 +629,7 @@ enum MpegTSState {
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typedef struct PESContext {
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int pid;
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MpegTSContext *ts;
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AVFormatContext *stream;
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AVStream *st;
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enum MpegTSState state;
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@ -648,7 +659,7 @@ static void mpegts_push_data(void *opaque,
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const uint8_t *buf, int buf_size, int is_start)
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{
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PESContext *pes = opaque;
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MpegTSContext *ts = pes->stream->priv_data;
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MpegTSContext *ts = pes->ts;
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AVStream *st;
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const uint8_t *p;
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int len, code, codec_type, codec_id;
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@ -779,9 +790,8 @@ static void mpegts_push_data(void *opaque,
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}
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}
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static int add_pes_stream(AVFormatContext *s, int pid)
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static int add_pes_stream(MpegTSContext *ts, int pid)
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{
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MpegTSContext *ts = s->priv_data;
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MpegTSFilter *tss;
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PESContext *pes;
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@ -789,7 +799,8 @@ static int add_pes_stream(AVFormatContext *s, int pid)
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pes = av_mallocz(sizeof(PESContext));
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if (!pes)
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return -1;
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pes->stream = s;
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pes->ts = ts;
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pes->stream = ts->stream;
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pes->pid = pid;
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tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes);
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if (!tss) {
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@ -800,9 +811,9 @@ static int add_pes_stream(AVFormatContext *s, int pid)
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}
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/* handle one TS packet */
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static void handle_packet(AVFormatContext *s, uint8_t *packet)
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static void handle_packet(MpegTSContext *ts, const uint8_t *packet)
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{
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MpegTSContext *ts = s->priv_data;
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AVFormatContext *s = ts->stream;
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MpegTSFilter *tss;
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int len, pid, cc, cc_ok, afc, is_start;
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const uint8_t *p, *p_end;
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@ -811,7 +822,7 @@ static void handle_packet(AVFormatContext *s, uint8_t *packet)
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is_start = packet[1] & 0x40;
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tss = ts->pids[pid];
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if (ts->auto_guess && tss == NULL && is_start) {
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add_pes_stream(s, pid);
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add_pes_stream(ts, pid);
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tss = ts->pids[pid];
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}
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if (!tss)
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@ -868,9 +879,8 @@ static void handle_packet(AVFormatContext *s, uint8_t *packet)
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/* XXX: try to find a better synchro over several packets (use
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get_packet_size() ?) */
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static int mpegts_resync(AVFormatContext *s)
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static int mpegts_resync(ByteIOContext *pb)
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{
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ByteIOContext *pb = &s->pb;
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int c, i;
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for(i = 0;i < MAX_RESYNC_SIZE; i++) {
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@ -886,13 +896,39 @@ static int mpegts_resync(AVFormatContext *s)
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return -1;
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}
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static int handle_packets(AVFormatContext *s, int nb_packets)
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/* return -1 if error or EOF. Return 0 if OK. */
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static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size)
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{
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MpegTSContext *ts = s->priv_data;
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int skip, len;
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for(;;) {
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len = get_buffer(pb, buf, TS_PACKET_SIZE);
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if (len != TS_PACKET_SIZE)
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return AVERROR_IO;
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/* check paquet sync byte */
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if (buf[0] != 0x47) {
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/* find a new packet start */
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url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR);
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if (mpegts_resync(pb) < 0)
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return AVERROR_INVALIDDATA;
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else
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continue;
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} else {
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skip = raw_packet_size - TS_PACKET_SIZE;
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if (skip > 0)
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url_fskip(pb, skip);
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break;
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}
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}
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return 0;
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}
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static int handle_packets(MpegTSContext *ts, int nb_packets)
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{
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AVFormatContext *s = ts->stream;
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ByteIOContext *pb = &s->pb;
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uint8_t packet[TS_FEC_PACKET_SIZE];
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int packet_num, len;
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int64_t pos;
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uint8_t packet[TS_PACKET_SIZE];
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int packet_num, ret;
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ts->stop_parse = 0;
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packet_num = 0;
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@ -902,20 +938,10 @@ static int handle_packets(AVFormatContext *s, int nb_packets)
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packet_num++;
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if (nb_packets != 0 && packet_num >= nb_packets)
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break;
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pos = url_ftell(pb);
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len = get_buffer(pb, packet, ts->raw_packet_size);
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if (len != ts->raw_packet_size)
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return AVERROR_IO;
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/* check paquet sync byte */
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if (packet[0] != 0x47) {
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/* find a new packet start */
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url_fseek(pb, -ts->raw_packet_size, SEEK_CUR);
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if (mpegts_resync(s) < 0)
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return AVERROR_INVALIDDATA;
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else
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continue;
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}
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handle_packet(s, packet);
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ret = read_packet(pb, packet, ts->raw_packet_size);
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if (ret != 0)
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return ret;
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handle_packet(ts, packet);
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}
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return 0;
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}
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@ -944,6 +970,35 @@ void set_service_cb(void *opaque, int ret)
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ts->stop_parse = 1;
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}
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/* return the 90 kHz PCR and the extension for the 27 MHz PCR. return
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(-1) if not available */
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static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,
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const uint8_t *packet)
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{
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int afc, len, flags;
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const uint8_t *p;
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unsigned int v;
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afc = (packet[3] >> 4) & 3;
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if (afc <= 1)
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return -1;
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p = packet + 4;
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len = p[0];
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p++;
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if (len == 0)
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return -1;
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flags = *p++;
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len--;
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if (!(flags & 0x10))
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return -1;
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if (len < 6)
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return -1;
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v = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
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*ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);
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*ppcr_low = ((p[4] & 1) << 8) | p[5];
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return 0;
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}
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static int mpegts_read_header(AVFormatContext *s,
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AVFormatParameters *ap)
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{
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@ -954,6 +1009,11 @@ static int mpegts_read_header(AVFormatContext *s,
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int64_t pos;
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MpegTSService *service;
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if (ap) {
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ts->mpeg2ts_raw = ap->mpeg2ts_raw;
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ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;
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}
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/* read the first 1024 bytes to get packet size */
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pos = url_ftell(pb);
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len = get_buffer(pb, buf, sizeof(buf));
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@ -962,57 +1022,112 @@ static int mpegts_read_header(AVFormatContext *s,
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ts->raw_packet_size = get_packet_size(buf, sizeof(buf));
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if (ts->raw_packet_size <= 0)
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goto fail;
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ts->stream = s;
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ts->auto_guess = 0;
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if (!ts->auto_guess) {
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ts->set_service_ret = -1;
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/* first do a scaning to get all the services */
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url_fseek(pb, pos, SEEK_SET);
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mpegts_scan_sdt(ts);
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if (!ts->mpeg2ts_raw) {
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/* normal demux */
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handle_packets(s, MAX_SCAN_PACKETS);
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if (!ts->auto_guess) {
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ts->set_service_ret = -1;
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if (ts->nb_services <= 0) {
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/* no SDT found, we try to look at the PAT */
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/* First remove the SDT filters from each PID */
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int i;
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for (i=0; i < NB_PID_MAX; i++) {
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if (ts->pids[i])
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mpegts_close_filter(ts, ts->pids[i]);
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}
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/* first do a scaning to get all the services */
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url_fseek(pb, pos, SEEK_SET);
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mpegts_scan_pat(ts);
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mpegts_scan_sdt(ts);
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handle_packets(s, MAX_SCAN_PACKETS);
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}
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if (ts->nb_services <= 0)
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return -1;
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/* tune to first service found */
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service = ts->services[0];
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sid = service->sid;
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handle_packets(ts, MAX_SCAN_PACKETS);
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if (ts->nb_services <= 0) {
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/* no SDT found, we try to look at the PAT */
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/* First remove the SDT filters from each PID */
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int i;
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for (i=0; i < NB_PID_MAX; i++) {
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if (ts->pids[i])
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mpegts_close_filter(ts, ts->pids[i]);
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}
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url_fseek(pb, pos, SEEK_SET);
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mpegts_scan_pat(ts);
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handle_packets(ts, MAX_SCAN_PACKETS);
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}
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if (ts->nb_services <= 0)
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return -1;
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/* tune to first service found */
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service = ts->services[0];
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sid = service->sid;
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#ifdef DEBUG_SI
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printf("tuning to '%s'\n", service->name);
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printf("tuning to '%s'\n", service->name);
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#endif
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/* now find the info for the first service if we found any,
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otherwise try to filter all PATs */
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url_fseek(pb, pos, SEEK_SET);
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ts->stream = s;
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mpegts_set_service(ts, sid, set_service_cb, ts);
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handle_packets(s, MAX_SCAN_PACKETS);
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/* if could not find service, exit */
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if (ts->set_service_ret != 0)
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return -1;
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/* now find the info for the first service if we found any,
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otherwise try to filter all PATs */
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url_fseek(pb, pos, SEEK_SET);
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mpegts_set_service(ts, sid, set_service_cb, ts);
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handle_packets(ts, MAX_SCAN_PACKETS);
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/* if could not find service, exit */
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if (ts->set_service_ret != 0)
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return -1;
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#ifdef DEBUG_SI
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printf("tuning done\n");
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printf("tuning done\n");
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#endif
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}
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s->ctx_flags |= AVFMTCTX_NOHEADER;
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} else {
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AVStream *st;
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int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;
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int64_t pcrs[2], pcr_h;
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int packet_count[2];
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uint8_t packet[TS_PACKET_SIZE];
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/* only read packets */
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s->pts_num = 1;
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s->pts_den = 27000000;
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st = av_new_stream(s, 0);
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if (!st)
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goto fail;
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st->codec.codec_type = CODEC_TYPE_DATA;
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st->codec.codec_id = CODEC_ID_MPEG2TS;
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/* we iterate until we find two PCRs to estimate the bitrate */
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pcr_pid = -1;
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nb_pcrs = 0;
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nb_packets = 0;
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for(;;) {
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ret = read_packet(&s->pb, packet, ts->raw_packet_size);
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if (ret < 0)
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return -1;
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pid = ((packet[1] & 0x1f) << 8) | packet[2];
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if ((pcr_pid == -1 || pcr_pid == pid) &&
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parse_pcr(&pcr_h, &pcr_l, packet) == 0) {
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pcr_pid = pid;
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packet_count[nb_pcrs] = nb_packets;
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pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
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nb_pcrs++;
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if (nb_pcrs >= 2)
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break;
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}
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nb_packets++;
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}
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/* NOTE1: the bitrate is computed without the FEC */
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/* NOTE2: it is only the bitrate of the start of the stream */
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ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
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ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];
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s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;
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st->codec.bit_rate = s->bit_rate;
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st->start_time = ts->cur_pcr * 1000000.0 / 27.0e6;
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#if 0
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printf("start=%0.3f pcr=%0.3f incr=%d\n",
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st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);
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#endif
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}
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@ -1022,12 +1137,62 @@ static int mpegts_read_header(AVFormatContext *s,
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return -1;
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}
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#define MAX_PACKET_READAHEAD ((128 * 1024) / 188)
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static int mpegts_raw_read_packet(AVFormatContext *s,
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AVPacket *pkt)
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{
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MpegTSContext *ts = s->priv_data;
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int ret, i;
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int64_t pcr_h, next_pcr_h, pos;
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int pcr_l, next_pcr_l;
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uint8_t pcr_buf[12];
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if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)
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return -ENOMEM;
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ret = read_packet(&s->pb, pkt->data, ts->raw_packet_size);
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if (ret < 0) {
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av_free_packet(pkt);
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return ret;
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}
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if (ts->mpeg2ts_compute_pcr) {
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/* compute exact PCR for each packet */
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if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {
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/* we read the next PCR (XXX: optimize it by using a bigger buffer */
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pos = url_ftell(&s->pb);
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for(i = 0; i < MAX_PACKET_READAHEAD; i++) {
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url_fseek(&s->pb, pos + i * ts->raw_packet_size, SEEK_SET);
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get_buffer(&s->pb, pcr_buf, 12);
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if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {
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/* XXX: not precise enough */
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ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) /
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(i + 1);
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break;
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}
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}
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url_fseek(&s->pb, pos, SEEK_SET);
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/* no next PCR found: we use previous increment */
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ts->cur_pcr = pcr_h * 300 + pcr_l;
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}
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pkt->pts = ts->cur_pcr;
|
||||
pkt->duration = ts->pcr_incr;
|
||||
ts->cur_pcr += ts->pcr_incr;
|
||||
}
|
||||
pkt->stream_index = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int mpegts_read_packet(AVFormatContext *s,
|
||||
AVPacket *pkt)
|
||||
{
|
||||
MpegTSContext *ts = s->priv_data;
|
||||
ts->pkt = pkt;
|
||||
return handle_packets(s, 0);
|
||||
|
||||
if (!ts->mpeg2ts_raw) {
|
||||
ts->pkt = pkt;
|
||||
return handle_packets(ts, 0);
|
||||
} else {
|
||||
return mpegts_raw_read_packet(s, pkt);
|
||||
}
|
||||
}
|
||||
|
||||
static int mpegts_read_close(AVFormatContext *s)
|
||||
@ -1039,6 +1204,59 @@ static int mpegts_read_close(AVFormatContext *s)
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**************************************************************/
|
||||
/* parsing functions - called from other demuxers such as RTP */
|
||||
|
||||
MpegTSContext *mpegts_parse_open(AVFormatContext *s)
|
||||
{
|
||||
MpegTSContext *ts;
|
||||
|
||||
ts = av_mallocz(sizeof(MpegTSContext));
|
||||
if (!ts)
|
||||
return NULL;
|
||||
/* no stream case, currently used by RTP */
|
||||
ts->raw_packet_size = TS_PACKET_SIZE;
|
||||
ts->stream = s;
|
||||
ts->auto_guess = 1;
|
||||
return ts;
|
||||
}
|
||||
|
||||
/* return the consumed length if a packet was output, or -1 if no
|
||||
packet is output */
|
||||
int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,
|
||||
const uint8_t *buf, int len)
|
||||
{
|
||||
int len1;
|
||||
|
||||
len1 = len;
|
||||
ts->pkt = pkt;
|
||||
ts->stop_parse = 0;
|
||||
for(;;) {
|
||||
if (ts->stop_parse)
|
||||
break;
|
||||
if (len < TS_PACKET_SIZE)
|
||||
return -1;
|
||||
if (buf[0] != 0x47) {
|
||||
buf--;
|
||||
len--;
|
||||
} else {
|
||||
handle_packet(ts, buf);
|
||||
buf += TS_PACKET_SIZE;
|
||||
len -= TS_PACKET_SIZE;
|
||||
}
|
||||
}
|
||||
return len1 - len;
|
||||
}
|
||||
|
||||
void mpegts_parse_close(MpegTSContext *ts)
|
||||
{
|
||||
int i;
|
||||
|
||||
for(i=0;i<NB_PID_MAX;i++)
|
||||
av_free(ts->pids[i]);
|
||||
av_free(ts);
|
||||
}
|
||||
|
||||
AVInputFormat mpegts_demux = {
|
||||
"mpegts",
|
||||
"MPEG2 transport stream format",
|
||||
@ -1047,7 +1265,7 @@ AVInputFormat mpegts_demux = {
|
||||
mpegts_read_header,
|
||||
mpegts_read_packet,
|
||||
mpegts_read_close,
|
||||
.flags = AVFMT_NOHEADER | AVFMT_SHOW_IDS,
|
||||
.flags = AVFMT_SHOW_IDS,
|
||||
};
|
||||
|
||||
int mpegts_init(void)
|
||||
|
||||
@ -42,3 +42,10 @@
|
||||
|
||||
unsigned int mpegts_crc32(const uint8_t *data, int len);
|
||||
extern AVOutputFormat mpegts_mux;
|
||||
|
||||
typedef struct MpegTSContext MpegTSContext;
|
||||
|
||||
MpegTSContext *mpegts_parse_open(AVFormatContext *s);
|
||||
int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,
|
||||
const uint8_t *buf, int len);
|
||||
void mpegts_parse_close(MpegTSContext *ts);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user