v4l2: rationalize tuner settings

The tuner index is determined by the input. The separate tuner index
setting was thus wrong and is removed.

The audio mode now defaults to primary language rather than being
unspecified. If this is not supported, it falls back to stereo, then
mono.

modules/access/v4l2/v4l2.h

@@ -111,6 +111,7 @@ struct buffer_t
 /* video.c */
 void ParseMRL(vlc_object_t *, const char *);
 int SetupAudio (vlc_object_t *, int, const struct v4l2_input *);
+int SetupTuner (vlc_object_t *, int, const struct v4l2_input *);
 block_t* GrabVideo(vlc_object_t *, demux_sys_t *);
 int InitVideo(vlc_object_t *, int fd, demux_sys_t *, bool demux);
 

modules/access/v4l2/video.c

@@ -273,17 +273,16 @@ static const char *const standards_user[] = { N_("Undefined"), N_("All"),
 };
 
 static const int i_tuner_audio_modes_list[] = {
-      -1, V4L2_TUNER_MODE_MONO, V4L2_TUNER_MODE_STEREO,
-      V4L2_TUNER_MODE_LANG1, V4L2_TUNER_MODE_LANG2,
-      V4L2_TUNER_MODE_SAP, V4L2_TUNER_MODE_LANG1_LANG2 };
+      V4L2_TUNER_MODE_MONO, V4L2_TUNER_MODE_STEREO,
+      V4L2_TUNER_MODE_LANG1, V4L2_TUNER_MODE_LANG2, V4L2_TUNER_MODE_LANG1_LANG2
+};
 static const char *const psz_tuner_audio_modes_list_text[] = {
-      N_("Unspecified"),
-      N_( "Mono" ),
-      N_( "Stereo" ),
-      N_( "Primary language (Analog TV tuners only)" ),
-      N_( "Secondary language (Analog TV tuners only)" ),
-      N_( "Second audio program (Analog TV tuners only)" ),
-      N_( "Primary language left, Secondary language right" ) };
+      N_("Mono"),
+      N_("Stereo"),
+      N_("Primary language"),
+      N_("Secondary language or program"),
+      N_("Dual mono" )
+};
 
 #define V4L2_DEFAULT "/dev/video0"
 
@@ -337,16 +336,13 @@ vlc_module_begin ()
     add_obsolete_bool( CFG_PREFIX "use-libv4l2" ) /* since 2.1.0 */
 
     set_section( N_( "Tuner" ), NULL )
-    add_integer( CFG_PREFIX "tuner", 0, TUNER_TEXT, TUNER_LONGTEXT,
-                 true )
-        change_integer_range( 0, 0xFFFFFFFE )
-        change_safe()
+    add_obsolete_integer( CFG_PREFIX "tuner" ) /* since 2.1.0 */
     add_integer( CFG_PREFIX "tuner-frequency", -1, FREQUENCY_TEXT,
                  FREQUENCY_LONGTEXT, true )
         change_integer_range( -1, 0xFFFFFFFE )
         change_safe()
-    add_integer( CFG_PREFIX "tuner-audio-mode", -1, TUNER_AUDIO_MODE_TEXT,
-                 TUNER_AUDIO_MODE_LONGTEXT, true )
+    add_integer( CFG_PREFIX "tuner-audio-mode", V4L2_TUNER_MODE_LANG1,
+                 TUNER_AUDIO_MODE_TEXT, TUNER_AUDIO_MODE_LONGTEXT, true )
         change_integer_list( i_tuner_audio_modes_list,
                              psz_tuner_audio_modes_list_text )
         change_safe()
@@ -572,8 +568,8 @@ int SetupAudio (vlc_object_t *obj, int fd,
         return -1;
     }
 
-    msg_Dbg (obj, "audio input %"PRIu32" (%s) is %s"
-             " (capabilities: 0x%08"PRIX32")", enumaudio.index, enumaudio.name,
+    msg_Dbg (obj, "audio input %s (%"PRIu32") is %s"
+             " (capabilities: 0x%08"PRIX32")", enumaudio.name, enumaudio.index,
              (enumaudio.capability & V4L2_AUDCAP_STEREO) ? "Stereo" : "Mono",
              enumaudio.capability);
     if (enumaudio.capability & V4L2_AUDCAP_AVL)
@@ -591,6 +587,113 @@ int SetupAudio (vlc_object_t *obj, int fd,
     return 0;
 }
 
+int SetupTuner (vlc_object_t *obj, int fd,
+                const struct v4l2_input *restrict input)
+{
+    switch (input->type)
+    {
+        case V4L2_INPUT_TYPE_TUNER:
+            msg_Dbg (obj, "tuning required: tuner %"PRIu32, input->tuner);
+            break;
+        case V4L2_INPUT_TYPE_CAMERA:
+            msg_Dbg (obj, "no tuning required (analog baseband input)");
+            return 0;
+        default:
+            msg_Err (obj, "unknown input tuning type %"PRIu32, input->type);
+            return 0; // hopefully we can stream regardless...
+    }
+
+    struct v4l2_tuner tuner = { .index = input->tuner };
+
+    if (v4l2_ioctl (fd, VIDIOC_G_TUNER, &tuner) < 0)
+    {
+        msg_Err (obj, "cannot get tuner %"PRIu32" properties: %m",
+                 input->tuner);
+        return -1;
+    }
+
+    /* NOTE: This is overkill. Only video devices currently work, so the
+     * type is always analog TV. */
+    const char *typename, *mult;
+    switch (tuner.type)
+    {
+        case V4L2_TUNER_RADIO:
+            typename = "Radio";
+            break;
+        case V4L2_TUNER_ANALOG_TV:
+            typename = "Analog TV";
+            break;
+        default:
+            typename = "unknown";
+    }
+    mult = (tuner.capability & V4L2_TUNER_CAP_LOW) ? "" : "k";
+
+    msg_Dbg (obj, "tuner %s (%"PRIu32") is %s", tuner.name, tuner.index,
+             typename);
+    msg_Dbg (obj, " ranges from %u.%u %sHz to %u.%c %sHz",
+             (tuner.rangelow * 125) >> 1, (tuner.rangelow & 1) * 5, mult,
+             (tuner.rangehigh * 125) >> 1, (tuner.rangehigh & 1) * 5,
+             mult);
+
+    /* TODO: only set video standard if the tuner requires it */
+
+    /* Configure the audio mode */
+    /* TODO: Ideally, L1 would be selected for stereo tuners, and L1_L2
+     * for mono tuners. When dual-mono is detected after tuning on a stereo
+     * tuner, we would fallback to L1_L2 too. Then we would flag dual-mono
+     * for the audio E/S. Unfortunately, we have no access to the audio E/S
+     * here (it belongs in the slave audio input...). */
+    tuner.audmode = var_InheritInteger (obj, CFG_PREFIX"tuner-audio-mode");
+    memset (tuner.reserved, 0, sizeof (tuner.reserved));
+
+    if (tuner.capability & V4L2_TUNER_CAP_LANG1)
+        msg_Dbg (obj, " supports primary audio language");
+    else if (tuner.audmode == V4L2_TUNER_MODE_LANG1)
+    {
+        msg_Warn (obj, " falling back to stereo mode");
+        tuner.audmode = V4L2_TUNER_MODE_STEREO;
+    }
+    if (tuner.capability & V4L2_TUNER_CAP_LANG2)
+        msg_Dbg (obj, " supports secondary audio language or program");
+    if (tuner.capability & V4L2_TUNER_CAP_STEREO)
+        msg_Dbg (obj, " supports stereo audio");
+    else if (tuner.audmode == V4L2_TUNER_MODE_STEREO)
+    {
+        msg_Warn (obj, " falling back to mono mode");
+        tuner.audmode = V4L2_TUNER_MODE_MONO;
+    }
+
+    if (v4l2_ioctl (fd, VIDIOC_S_TUNER, &tuner) < 0)
+    {
+        msg_Err (obj, "cannot set tuner %"PRIu32" audio mode: %m",
+                 input->tuner);
+        return -1;
+    }
+    msg_Dbg (obj, "tuner %"PRIu32" audio mode %u set", input->tuner,
+             tuner.audmode);
+
+    /* Tune to the requested frequency */
+    uint32_t freq = var_InheritInteger (obj, CFG_PREFIX"tuner-frequency");
+    if (freq != (uint32_t)-1)
+    {
+        struct v4l2_frequency frequency = {
+            .tuner = input->tuner,
+            .type = V4L2_TUNER_ANALOG_TV,
+            .frequency = freq * 125 / 2
+        };
+
+        if (v4l2_ioctl (fd, VIDIOC_S_FREQUENCY, &frequency) < 0)
+        {
+            msg_Err (obj, "cannot tuner tuner %u to frequency %u %sHz: %m",
+                     input->tuner, freq, mult);
+            return -1;
+        }
+    }
+    msg_Dbg (obj, "tuner %"PRIu32" tuned to frequency %"PRIu32" %sHz",
+             input->tuner, freq, mult);
+    return 0;
+}
+
 /*****************************************************************************
  * GrabVideo: Grab a video frame
  *****************************************************************************/
@@ -937,79 +1040,8 @@ int InitVideo( vlc_object_t *p_obj, int i_fd, demux_sys_t *p_sys,
     else
         bottom_first = false;
 
-    /* Set audio input */
     SetupAudio (p_obj, i_fd, &input);
-
-    /* List tuner caps */
-    if( cap.capabilities & V4L2_CAP_TUNER )
-    {
-        struct v4l2_tuner tuner;
-        uint32_t idx = var_CreateGetInteger( p_obj, CFG_PREFIX"tuner" );
-        enum v4l2_tuner_type type = V4L2_TUNER_RADIO;
-
-        tuner.index = 0;
-        while( v4l2_ioctl( i_fd, VIDIOC_G_TUNER, &tuner ) >= 0 )
-        {
-            if( tuner.index == idx )
-                type = tuner.type;
-
-            const char *unit =
-                (tuner.capability & V4L2_TUNER_CAP_LOW) ? "Hz" : "kHz";
-            msg_Dbg( p_obj, "tuner %u (%s) has type: %s, "
-                     "frequency range: %.1f %s -> %.1f %s", tuner.index,
-                     tuner.name,
-                     tuner.type == V4L2_TUNER_RADIO ? "Radio" : "Analog TV",
-                     tuner.rangelow * 62.5, unit,
-                     tuner.rangehigh * 62.5, unit );
-
-            struct v4l2_frequency frequency = { .tuner = tuner.index };
-            if( v4l2_ioctl( i_fd, VIDIOC_G_FREQUENCY, &frequency ) < 0 )
-            {
-                msg_Err( p_obj, "cannot get tuner frequency: %m" );
-                return -1;
-            }
-            msg_Dbg( p_obj, "tuner %u (%s) frequency: %.1f %s", tuner.index,
-                     tuner.name, frequency.frequency * 62.5, unit );
-            tuner.index++;
-        }
-
-        /* Tune the tuner */
-        uint32_t freq = var_InheritInteger( p_obj,
-                                            CFG_PREFIX"tuner-frequency" );
-        if( freq != (uint32_t)-1 )
-        {
-            struct v4l2_frequency frequency = {
-                .tuner = idx,
-                .type = type,
-                .frequency = freq / 62.5,
-            };
-
-            if( v4l2_ioctl( i_fd, VIDIOC_S_FREQUENCY, &frequency ) < 0 )
-            {
-                msg_Err( p_obj, "cannot set tuner frequency: %m" );
-                return -1;
-            }
-            msg_Dbg( p_obj, "tuner frequency set" );
-        }
-
-        /* Set the tuner audio mode */
-        int32_t audmode = var_InheritInteger( p_obj,
-                                              CFG_PREFIX"tuner-audio-mode" );
-        if( audmode >= 0 )
-        {
-            struct v4l2_tuner tuner = {
-                .index = idx,
-                .audmode = audmode,
-            };
-
-            if( v4l2_ioctl( i_fd, VIDIOC_S_TUNER, &tuner ) < 0 )
-            {
-                msg_Err( p_obj, "cannot set tuner audio mode: %m" );
-                return -1;
-            }
-            msg_Dbg( p_obj, "tuner audio mode set" );
-        }
-    }
+    SetupTuner (p_obj, i_fd, &input);
 
     /* Probe for available chromas */
     struct v4l2_fmtdesc *codecs = NULL;