stream_dvb: Also demux PMT if possible, reactivate TPID parsing.

If VDR-channel-config is used, we know the service_id.
Using that, PMT can be extracted from PAT (code for that
inspired by szap-s2 again).
For this, we need to demux PAT with a special filter-setup,
and once PMT was found it can be added to the PID-list.
PMT is only resolved the first time one tunes to a channel,
then stored in the channel-list in memory.

With PMT available, ffmpeg can safely decode the teletext-pids.

4 files changed, 113 insertions, 12 deletions

diff --git a/stream/dvb_tune.c b/stream/dvb_tune.c
index 673109152a..873ac91ec5 100644
--- a/stream/dvb_tune.c
+++ b/stream/dvb_tune.c
@@ -187,6 +187,74 @@ int dvb_set_ts_filt(dvb_priv_t *priv, int fd, uint16_t pid, dmx_pes_type_t pesty
         return 1;
 }
 
+int dvb_get_pmt_pid(dvb_priv_t *priv, int card, int service_id) {
+  /* We need special filters on the demux, 
+     so open one locally, and close also here. */
+  char demux_dev[32];
+  sprintf(demux_dev, "/dev/dvb/adapter%d/demux0", card);
+  
+  struct dmx_sct_filter_params fparams;
+  
+  memset(&fparams, 0, sizeof(fparams));
+  fparams.pid = 0;
+  fparams.filter.filter[0] = 0x00;
+  fparams.filter.mask[0] = 0xff;
+  fparams.timeout = 0;
+  fparams.flags = DMX_IMMEDIATE_START | DMX_CHECK_CRC;
+
+  int pat_fd;
+  if ((pat_fd = open(demux_dev, O_RDWR)) < 0) {
+    MP_ERR(priv, "Opening PAT DEMUX failed, error: %d", errno);
+    return -1;
+  }
+  
+  if (ioctl(pat_fd, DMX_SET_FILTER, &fparams) == -1) {
+    MP_ERR(priv, "ioctl DMX_SET_FILTER failed, error: %d", errno);
+    close(pat_fd);
+    return -1;
+  }
+    
+  int bytes_read;
+  int section_length;
+  unsigned char buft[4096];
+  unsigned char *bufptr = buft;
+
+  int pmt_pid = -1;
+
+  bool pat_read = false;
+  while (!pat_read) {
+    if (((bytes_read = read(pat_fd, bufptr, sizeof(buft))) < 0) && errno == EOVERFLOW)
+      bytes_read = read(pat_fd, bufptr, sizeof(buft));
+    if (bytes_read < 0) {
+      MP_ERR(priv, "PAT: read_sections: read error: %d", errno);
+      close(pat_fd);
+      return -1;
+    }
+    
+    section_length = ((bufptr[1] & 0x0f) << 8) | bufptr[2];
+    if (bytes_read != section_length + 3) {
+      continue;
+    }
+    
+    bufptr += 8;
+    section_length -= 8;
+    
+    /* assumes one section contains the whole pat */
+    pat_read = true; 
+    while (section_length > 0) {
+      int this_service_id = (bufptr[0] << 8) | bufptr[1];
+      if (this_service_id == service_id) {
+        pmt_pid = ((bufptr[2] & 0x1f) << 8) | bufptr[3];
+        section_length = 0;
+      }
+      bufptr += 4;
+      section_length -= 4;
+    }
+  }
+  close(pat_fd);
+  
+  return pmt_pid;
+}
 
 int dvb_demux_stop(int fd)
 {
diff --git a/stream/dvb_tune.h b/stream/dvb_tune.h
index 2d2f4e6589..50c598f810 100644
--- a/stream/dvb_tune.h
+++ b/stream/dvb_tune.h
@@ -27,6 +27,7 @@ int dvb_get_tuner_type(int fe_fd, struct mp_log *log);
 int dvb_open_devices(dvb_priv_t *priv, int n, int demux_cnt);
 int dvb_fix_demuxes(dvb_priv_t *priv, int cnt);
 int dvb_set_ts_filt(dvb_priv_t *priv, int fd, uint16_t pid, dmx_pes_type_t pestype);
+int dvb_get_pmt_pid(dvb_priv_t *priv, int card, int service_id);
 int dvb_demux_stop(int fd);
 int dvb_demux_start(int fd);
 int dvb_tune(dvb_priv_t *priv, int freq, char pol, int srate, int diseqc,
diff --git a/stream/dvbin.h b/stream/dvbin.h
index 0b2cc27537..61bc0b1e18 100644
--- a/stream/dvbin.h
+++ b/stream/dvbin.h
@@ -65,6 +65,7 @@ typedef struct {
         int                             tpid, dpid1, dpid2, progid, ca, pids[DMX_FILTER_SIZE], pids_cnt;
         bool                            is_dvb_s2;
         int                             stream_id;
+        int                             service_id;
         fe_spectral_inversion_t         inv;
         fe_modulation_t                 mod;
         fe_transmit_mode_t              trans;
diff --git a/stream/stream_dvb.c b/stream/stream_dvb.c
index 7ebcd8fc1b..6a50bb66f5 100644
--- a/stream/stream_dvb.c
+++ b/stream/stream_dvb.c
@@ -214,7 +214,7 @@ static dvb_channels_list *dvb_get_channels(struct mp_log *log, char *filename, i
         const char *ter_conf = "%d:%255[^:]:%255[^:]:%255[^:]:%255[^:]:%255[^:]:%255[^:]:%255[^:]:%255[^:]:%255[^:]:%255[^:]\n";
         const char *atsc_conf = "%d:%255[^:]:%255[^:]:%255[^:]\n";
 
-        const char *vdr_conf = "%d:%255[^:]:%255[^:]:%d:%255[^:]:%255[^:]:%255[^:]:%*255[^:]:%*d:%*d:%*d:%*d\n%n";
+        const char *vdr_conf = "%d:%255[^:]:%255[^:]:%d:%255[^:]:%255[^:]:%255[^:]:%*255[^:]:%d:%*d:%*d:%*d\n%n";
 
         mp_verbose(log, "CONFIG_READ FILE: %s, type: %d\n", filename, type);
         if((f=fopen(filename, "r"))==NULL)
@@ -267,13 +267,14 @@ static dvb_channels_list *dvb_get_channels(struct mp_log *log, char *filename, i
                 ptr->pids_cnt = 0;
                 ptr->freq = 0;
                 ptr->is_dvb_s2 = false;
+                ptr->service_id = -1;
                 ptr->stream_id = NO_STREAM_ID_FILTER;
                 ptr->inv = INVERSION_AUTO;
 
                 // Check if VDR-type channels.conf-line - then full line is consumed by the scan. 
                 int num_chars = 0;
                 fields = sscanf(&line[k], vdr_conf,
-                                &ptr->freq, vdr_par_str, vdr_loc_str, &ptr->srate, vpid_str, apid_str, tpid_str, &num_chars);
+                                &ptr->freq, vdr_par_str, vdr_loc_str, &ptr->srate, vpid_str, apid_str, tpid_str, &ptr->service_id, &num_chars);
                 
                 if (num_chars == strlen(&line[k])) {
                   // It's a VDR-style config line.
@@ -302,9 +303,9 @@ static dvb_channels_list *dvb_get_channels(struct mp_log *log, char *filename, i
                       }
                     }
                     
-                    mp_verbose(log, "SAT, NUM: %d, NUM_FIELDS: %d, NAME: %s, FREQ: %d, SRATE: %d, POL: %c, DISEQC: %d, S2: %s, StreamID: %d",
+                    mp_verbose(log, "SAT, NUM: %d, NUM_FIELDS: %d, NAME: %s, FREQ: %d, SRATE: %d, POL: %c, DISEQC: %d, S2: %s, StreamID: %d, SID: %d",
                                list->NUM_CHANNELS, fields, ptr->name, ptr->freq, ptr->srate, ptr->pol,  ptr->diseqc,
-                               ptr->is_dvb_s2 ? "yes" : "no", ptr->stream_id);
+                               ptr->is_dvb_s2 ? "yes" : "no", ptr->stream_id, ptr->service_id);
                   } else {
                     mp_verbose(log, "VDR, NUM: %d, NUM_FIELDS: %d, NAME: %s, FREQ: %d, SRATE: %d",
                                list->NUM_CHANNELS, fields, ptr->name, ptr->freq, ptr->srate);
@@ -355,12 +356,14 @@ static dvb_channels_list *dvb_get_channels(struct mp_log *log, char *filename, i
                 if (parse_pid_string(log, apid_str, ptr)) {
                   fields++;
                 }
-                /*
-                  // FIXME: Teletext PID excluded for now, seems misdetected as mp3. 
-                if (parse_pid_string(log, tpid_str, ptr)) {
-                  fields++;
+                /* If we do not know the service_id, PMT can not be extracted.
+                   Teletext decoding will fail without PMT. */
+                if (ptr->service_id != -1) {
+                  if (parse_pid_string(log, tpid_str, ptr)) {
+                    fields++;
+                  }
                 }
-                */
+                
                 
                 if((fields < 2) || (ptr->pids_cnt <= 0) || (ptr->freq == 0) || (strlen(ptr->name) == 0))
                   continue;
@@ -383,6 +386,15 @@ static dvb_channels_list *dvb_get_channels(struct mp_log *log, char *filename, i
                         ptr->pids[ptr->pids_cnt] = 0;   //PID 0 is the PAT
                         ptr->pids_cnt++;
                 }
+
+                if (ptr->service_id != -1) {
+                  /* We have the PMT-PID in addition. 
+                     This will be found later, when we tune to the channel.
+                     Push back here to create the additional demux. */
+                  ptr->pids[ptr->pids_cnt] = -1; // Placeholder. 
+                  ptr->pids_cnt++;
+                }
+                
                 mp_verbose(log, " PIDS: ");
                 for(cnt = 0; cnt < ptr->pids_cnt; cnt++)
                         mp_verbose(log, " %d ", ptr->pids[cnt]);
@@ -663,13 +675,32 @@ int dvb_set_channel(stream_t *stream, int card, int n)
 
         priv->last_freq = channel->freq;
         priv->is_on = 1;
+        
+        if (channel->service_id != -1) {
+          /* We need the PMT-PID in addition. 
+             If it has not yet beem resolved, do it now. */
+          for (i = 0; i < channel->pids_cnt; i++) {
+            if (channel->pids[i] == -1) {
+              MP_VERBOSE(stream, "DVB_SET_CHANNEL: PMT-PID for service %d not resolved yet, parsing PAT...\n", channel->service_id);
+              int pmt_pid = dvb_get_pmt_pid(priv, card, channel->service_id);
+              MP_VERBOSE(stream, "DVB_SET_CHANNEL: Found PMT-PID: %d\n", pmt_pid);
+              channel->pids[i] = pmt_pid;
+            }
+          }
+        }
 
-        //sets demux filters and restart the stream
+        // sets demux filters and restart the stream
         for(i = 0; i < channel->pids_cnt; i++)
         {
-          if (!dvb_set_ts_filt(priv,priv->demux_fds[i], channel->pids[i], DMX_PES_OTHER))
-            return 0;
+          if (channel->pids[i] == -1) {
+            // In case PMT was not resolved, skip it here.
+            MP_ERR(stream, "DVB_SET_CHANNEL: PMT-PID not found, teletext-decoding may fail.\n");
+          } else {
+            if (!dvb_set_ts_filt(priv,priv->demux_fds[i], channel->pids[i], DMX_PES_OTHER)) 
+              return 0;
+          }
         }
+
         return 1;
 }