demuxer: introduce a general stream struct

There are different C types for each stream type: sh_video for video,
sh_audio for audio, sh_sub for sub. There is no type that handles all
stream types in a generic way. Instead, there's a macro SH_COMMON, that
is used to define common fields for all 3 stream structs. Accessing
the common fields is hard if you want to be independent from the stream
type.

Introduce an actual generic stream struct (struct sh_stream), which is
supposed to unify all 3 stream types one day. Once all fields defined
by SH_COMMON have been moved into sh_stream, the transition is complete.

Move some fields into sh_stream, and rewrite osd_show_tracks to use
them.

5 files changed, 123 insertions, 67 deletions

diff --git a/libmpdemux/demux_lavf.c b/libmpdemux/demux_lavf.c
index 42130dd677..b7a8029927 100644
--- a/libmpdemux/demux_lavf.c
+++ b/libmpdemux/demux_lavf.c
@@ -309,7 +309,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
         sh_audio = new_sh_audio_aid(demuxer, i, priv->audio_streams);
         if (!sh_audio)
             break;
-        sh_audio->demuxer_id = i;
+        sh_audio->gsh->demuxer_id = i;
         sh_audio->demuxer_codecname = codec_name;
         stream_type = "audio";
         priv->astreams[priv->audio_streams] = i;
@@ -366,7 +366,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
             break;
         }
         if (title && title->value) {
-            sh_audio->title = talloc_strdup(sh_audio, title->value);
+            sh_audio->gsh->title = talloc_strdup(sh_audio, title->value);
             mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_AID_%d_NAME=%s\n",
                    priv->audio_streams, title->value);
         }
@@ -376,7 +376,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
                    priv->audio_streams, sh_audio->lang);
         }
         if (st->disposition & AV_DISPOSITION_DEFAULT)
-            sh_audio->default_track = 1;
+            sh_audio->gsh->default_track = 1;
         if (mp_msg_test(MSGT_HEADER, MSGL_V))
             print_wave_header(sh_audio->wf, MSGL_V);
         st->discard = AVDISCARD_ALL;
@@ -389,7 +389,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
         sh_video = new_sh_video_vid(demuxer, i, priv->video_streams);
         if (!sh_video)
             break;
-        sh_video->demuxer_id = i;
+        sh_video->gsh->demuxer_id = i;
         sh_video->demuxer_codecname = codec_name;
         stream_type = "video";
         priv->vstreams[priv->video_streams] = i;
@@ -454,7 +454,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
                     / (float)(codec->height * codec->sample_aspect_ratio.den);
         sh_video->i_bps = codec->bit_rate / 8;
         if (title && title->value) {
-            sh_video->title = talloc_strdup(sh_video, title->value);
+            sh_video->gsh->title = talloc_strdup(sh_video, title->value);
             mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_VID_%d_NAME=%s\n",
                    priv->video_streams, title->value);
         }
@@ -502,7 +502,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
         sh_sub = new_sh_sub_sid(demuxer, i, priv->sub_streams);
         if (!sh_sub)
             break;
-        sh_sub->demuxer_id = i;
+        sh_sub->gsh->demuxer_id = i;
         sh_sub->demuxer_codecname = codec_name;
         stream_type = "subtitle";
         priv->sstreams[priv->sub_streams] = i;
@@ -514,7 +514,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
             sh_sub->extradata_len = codec->extradata_size;
         }
         if (title && title->value) {
-            sh_sub->title = talloc_strdup(sh_sub, title->value);
+            sh_sub->gsh->title = talloc_strdup(sh_sub, title->value);
             mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_SID_%d_NAME=%s\n",
                    priv->sub_streams, title->value);
         }
@@ -524,7 +524,7 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
                    priv->sub_streams, sh_sub->lang);
         }
         if (st->disposition & AV_DISPOSITION_DEFAULT)
-            sh_sub->default_track = 1;
+            sh_sub->gsh->default_track = 1;
         stream_id = priv->sub_streams++;
         break;
     }
diff --git a/libmpdemux/demux_mkv.c b/libmpdemux/demux_mkv.c
index 49168e88e4..bf6a53a14f 100644
--- a/libmpdemux/demux_mkv.c
+++ b/libmpdemux/demux_mkv.c
@@ -1271,9 +1271,9 @@ static int demux_mkv_open_video(demuxer_t *demuxer, mkv_track_t *track,
     }
 
     sh_v = new_sh_video(demuxer, vid);
-    sh_v->demuxer_id = track->tnum;
+    sh_v->gsh->demuxer_id = track->tnum;
     sh_v->demuxer_codecname = track->codec_id;
-    sh_v->title = talloc_strdup(sh_v, track->name);
+    sh_v->gsh->title = talloc_strdup(sh_v, track->name);
     sh_v->bih = bih;
     sh_v->format = sh_v->bih->biCompression;
     if (track->v_frate == 0.0)
@@ -1344,10 +1344,10 @@ static int demux_mkv_open_audio(demuxer_t *demuxer, mkv_track_t *track,
 
     if (track->language && (strcmp(track->language, "und") != 0))
         sh_a->lang = talloc_strdup(sh_a, track->language);
-    sh_a->demuxer_id = track->tnum;
+    sh_a->gsh->demuxer_id = track->tnum;
     sh_a->demuxer_codecname = track->codec_id;
-    sh_a->title = talloc_strdup(sh_a, track->name);
-    sh_a->default_track = track->default_track;
+    sh_a->gsh->title = talloc_strdup(sh_a, track->name);
+    sh_a->gsh->default_track = track->default_track;
     sh_a->ds = demuxer->audio;
     if (track->ms_compat) {
         if (track->private_size < sizeof(*sh_a->wf))
@@ -1583,7 +1583,7 @@ static int demux_mkv_open_sub(demuxer_t *demuxer, mkv_track_t *track,
         int size;
         uint8_t *buffer;
         sh_sub_t *sh = new_sh_sub(demuxer, sid);
-        sh->demuxer_id = track->tnum;
+        sh->gsh->demuxer_id = track->tnum;
         sh->demuxer_codecname = track->codec_id;
         track->sh_sub = sh;
         sh->type = track->subtitle_type;
@@ -1600,8 +1600,8 @@ static int demux_mkv_open_sub(demuxer_t *demuxer, mkv_track_t *track,
         sh->extradata_len = track->private_size;
         if (track->language && (strcmp(track->language, "und") != 0))
             sh->lang = talloc_strdup(sh, track->language);
-        sh->title = talloc_strdup(sh, track->name);
-        sh->default_track = track->default_track;
+        sh->gsh->title = talloc_strdup(sh, track->name);
+        sh->gsh->default_track = track->default_track;
     } else {
         mp_tmsg(MSGT_DEMUX, MSGL_ERR,
                 "[mkv] Subtitle type '%s' is not supported.\n",
diff --git a/libmpdemux/demuxer.c b/libmpdemux/demuxer.c
index a9a827dd7a..078699fad7 100644
--- a/libmpdemux/demuxer.c
+++ b/libmpdemux/demuxer.c
@@ -284,6 +284,58 @@ const char *sh_sub_type2str(int type)
     return "unknown";
 }
 
+static struct sh_stream *new_sh_stream(demuxer_t *demuxer,
+                                       enum stream_type type,
+                                       int stream_index,
+                                       int tid)
+{
+    struct sh_stream *sh = talloc_struct(demuxer, struct sh_stream, {
+        .type = type,
+        .index = demuxer->num_streams,
+        .demuxer_id = demuxer->new_stream_id++, // possibly temporary value only
+        .tid = tid,
+        .stream_index = stream_index,
+        .opts = demuxer->opts,
+    });
+    MP_TARRAY_APPEND(demuxer, demuxer->streams, demuxer->num_streams, sh);
+    switch (sh->type) {
+        case STREAM_VIDEO: {
+            struct sh_video *sht = talloc_zero(demuxer, struct sh_video);
+            sht->vid = sh->tid;
+            sht->ds = demuxer->video;
+            sh->video = sht;
+            sh->common_header = (struct sh_common *) sht;
+            demuxer->v_streams[sh->stream_index] = sht;
+            break;
+        }
+        case STREAM_AUDIO: {
+            struct sh_audio *sht = talloc_zero(demuxer, struct sh_audio);
+            sht->aid = tid;
+            sht->ds = demuxer->audio;
+            sht->samplesize = 2;
+            sht->sample_format = AF_FORMAT_S16_NE;
+            sh->audio = sht;
+            sh->common_header = (struct sh_common *) sht;
+            demuxer->a_streams[sh->stream_index] = sht;
+            break;
+        }
+        case STREAM_SUB: {
+            struct sh_sub *sht = talloc_zero(demuxer, struct sh_sub);
+            sht->sid = tid;
+            sht->ds = demuxer->sub;
+            sh->sub = sht;
+            sh->common_header = (struct sh_common *) sht;
+            demuxer->s_streams[sh->stream_index] = sht;
+            break;
+        }
+        default: assert(false);
+    }
+    sh->common_header->id = sh->tid;
+    sh->common_header->opts = sh->opts;
+    sh->common_header->gsh = sh;
+    return sh;
+}
+
 sh_sub_t *new_sh_sub_sid(demuxer_t *demuxer, int id, int sid)
 {
     if (id > MAX_S_STREAMS - 1 || id < 0) {
@@ -295,14 +347,7 @@ sh_sub_t *new_sh_sub_sid(demuxer_t *demuxer, int id, int sid)
     if (demuxer->s_streams[id])
         mp_msg(MSGT_DEMUXER, MSGL_WARN, "Sub stream %i redefined\n", id);
     else {
-        struct sh_sub *sh = talloc_zero(demuxer, struct sh_sub);
-        demuxer->s_streams[id] = sh;
-        sh->stream_type = STREAM_SUBTITLE;
-        sh->demuxer_id = demuxer->new_stream_id++;
-        sh->id = sid;
-        sh->index = id;
-        sh->sid = sid;
-        sh->opts = demuxer->opts;
+        new_sh_stream(demuxer, STREAM_SUB, id, sid);
         mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_SUBTITLE_ID=%d\n", sid);
     }
     return demuxer->s_streams[id];
@@ -328,18 +373,7 @@ sh_audio_t *new_sh_audio_aid(demuxer_t *demuxer, int id, int aid)
         mp_tmsg(MSGT_DEMUXER, MSGL_WARN, "WARNING: Audio stream header %d redefined.\n", id);
     } else {
         mp_tmsg(MSGT_DEMUXER, MSGL_V, "==> Found audio stream: %d\n", id);
-        struct sh_audio *sh = talloc_zero(demuxer, struct sh_audio);
-        demuxer->a_streams[id] = sh;
-        sh->stream_type = STREAM_AUDIO;
-        sh->demuxer_id = demuxer->new_stream_id++;
-        sh->id = aid;
-        sh->index = id;
-        sh->aid = aid;
-        sh->ds = demuxer->audio;
-        // set some defaults
-        sh->samplesize = 2;
-        sh->sample_format = AF_FORMAT_S16_NE;
-        sh->opts = demuxer->opts;
+        new_sh_stream(demuxer, STREAM_AUDIO, id, aid);
         mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_AUDIO_ID=%d\n", aid);
     }
     return demuxer->a_streams[id];
@@ -368,15 +402,7 @@ sh_video_t *new_sh_video_vid(demuxer_t *demuxer, int id, int vid)
         mp_tmsg(MSGT_DEMUXER, MSGL_WARN, "WARNING: Video stream header %d redefined.\n", id);
     else {
         mp_tmsg(MSGT_DEMUXER, MSGL_V, "==> Found video stream: %d\n", id);
-        struct sh_video *sh = talloc_zero(demuxer, struct sh_video);
-        demuxer->v_streams[id] = sh;
-        sh->stream_type = STREAM_VIDEO;
-        sh->demuxer_id = demuxer->new_stream_id++;
-        sh->id = vid;
-        sh->index = id;
-        sh->vid = vid;
-        sh->ds = demuxer->video;
-        sh->opts = demuxer->opts;
+        new_sh_stream(demuxer, STREAM_VIDEO, id, vid);
         mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_VIDEO_ID=%d\n", vid);
     }
     return demuxer->v_streams[id];
@@ -1452,7 +1478,7 @@ int demuxer_set_angle(demuxer_t *demuxer, int angle)
     return angle;
 }
 
-char *demuxer_audio_lang(demuxer_t *d, int id)
+static char *demuxer_audio_lang(demuxer_t *d, int id)
 {
     struct stream_lang_req req;
     sh_audio_t *sh;
@@ -1470,7 +1496,7 @@ char *demuxer_audio_lang(demuxer_t *d, int id)
     return NULL;
 }
 
-char *demuxer_sub_lang(demuxer_t *d, int id)
+static char *demuxer_sub_lang(demuxer_t *d, int id)
 {
     struct stream_lang_req req;
     sh_sub_t *sh;
@@ -1488,6 +1514,15 @@ char *demuxer_sub_lang(demuxer_t *d, int id)
     return NULL;
 }
 
+char *demuxer_stream_lang(demuxer_t *d, struct sh_stream *s)
+{
+    switch (s->type) {
+    case STREAM_AUDIO: return demuxer_audio_lang(d, s->stream_index);
+    case STREAM_SUB: return demuxer_sub_lang(d, s->stream_index);
+    default: return NULL;
+    }
+}
+
 int demuxer_audio_track_by_lang_and_default(struct demuxer *d, char **langt)
 {
     int n = 0;
@@ -1497,7 +1532,7 @@ int demuxer_audio_track_by_lang_and_default(struct demuxer *d, char **langt)
         for (int i = 0; i < MAX_A_STREAMS; i++) {
             struct sh_audio *sh = d->a_streams[i];
             if (sh && (!lang || sh->lang && !strcmp(lang, sh->lang))) {
-                if (sh->default_track)
+                if (sh->gsh->default_track)
                     return sh->aid;
                 if (id < 0)
                     id = sh->aid;
@@ -1519,7 +1554,7 @@ int demuxer_sub_track_by_lang_and_default(struct demuxer *d, char **langt)
         for (int i = 0; i < MAX_S_STREAMS; i++) {
             struct sh_sub *sh = d->s_streams[i];
             if (sh && (!lang || sh->lang && !strcmp(lang, sh->lang))) {
-                if (sh->default_track)
+                if (sh->gsh->default_track)
                     return sh->sid;
                 if (id < 0)
                     id = sh->sid;
diff --git a/libmpdemux/demuxer.h b/libmpdemux/demuxer.h
index 285ac3a7af..9b63eb63ac 100644
--- a/libmpdemux/demuxer.h
+++ b/libmpdemux/demuxer.h
@@ -147,9 +147,10 @@ typedef struct demuxer_info {
     char *copyright;
 } demuxer_info_t;
 
-#define MAX_A_STREAMS 256
-#define MAX_V_STREAMS 256
-#define MAX_S_STREAMS 256
+#define MAX_SH_STREAMS 256
+#define MAX_A_STREAMS MAX_SH_STREAMS
+#define MAX_V_STREAMS MAX_SH_STREAMS
+#define MAX_S_STREAMS MAX_SH_STREAMS
 
 struct demuxer;
 
@@ -244,9 +245,12 @@ typedef struct demuxer {
     struct demux_stream *sub;   // dvd subtitle buffer/demuxer
 
     // stream headers:
-    struct sh_audio *a_streams[MAX_A_STREAMS];
-    struct sh_video *v_streams[MAX_V_STREAMS];
-    struct sh_sub   *s_streams[MAX_S_STREAMS];
+    struct sh_audio *a_streams[MAX_SH_STREAMS];
+    struct sh_video *v_streams[MAX_SH_STREAMS];
+    struct sh_sub   *s_streams[MAX_SH_STREAMS];
+
+    struct sh_stream **streams;
+    int num_streams;
 
     int num_titles;
 
@@ -415,7 +419,6 @@ int demuxer_angles_count(struct demuxer *demuxer);
 int demuxer_audio_track_by_lang_and_default(struct demuxer *d, char **langt);
 int demuxer_sub_track_by_lang_and_default(struct demuxer *d, char **langt);
 
-char *demuxer_audio_lang(demuxer_t *d, int id);
-char *demuxer_sub_lang(demuxer_t *d, int id);
+char *demuxer_stream_lang(demuxer_t *d, struct sh_stream *s);
 
 #endif /* MPLAYER_DEMUXER_H */
diff --git a/libmpdemux/stheader.h b/libmpdemux/stheader.h
index c93bcf8185..c0bf9e4db0 100644
--- a/libmpdemux/stheader.h
+++ b/libmpdemux/stheader.h
@@ -26,23 +26,43 @@
 struct MPOpts;
 struct demuxer;
 
-enum STREAM_TYPE {
+enum stream_type {
     STREAM_VIDEO = 1,
     STREAM_AUDIO,
-    STREAM_SUBTITLE,
+    STREAM_SUB,
 };
 
 // Stream headers:
 
-// id: the type specific id, e.g. aid or sid
-// index: index into stream array (currently one array per type)
-// demuxer_id: demuxer specific ID (-1 if unknown, otherwise >= 0)
+struct sh_stream {
+    enum stream_type type;
+    // Index into demuxer->streams.
+    int index;
+    // The (possibly) type specific id, e.g. aid or sid.
+    int tid;
+    // Index into stream array (currently one array per type, e.g. a_streams).
+    int stream_index;
+    // Demuxer specific ID (-1 if unknown, otherwise >= 0).
+    int demuxer_id;
+    // Abomination.
+    struct sh_common *common_header;
+    // One of these is non-NULL, the others are NULL, depending on the stream
+    // type.
+    struct sh_audio *audio;
+    struct sh_video *video;
+    struct sh_sub *sub;
+
+    char *title;
+    bool default_track;
+
+    // shouldn't exist type of stuff
+    struct MPOpts *opts;
+};
+
 
 #define SH_COMMON                                                       \
-    enum STREAM_TYPE stream_type;                                       \
     int id;                                                             \
-    int index;                                                          \
-    int demuxer_id;                                                     \
+    struct sh_stream *gsh;                                              \
     const char *demuxer_codecname;                                      \
     struct MPOpts *opts;                                                \
     struct demux_stream *ds;                                            \
@@ -64,8 +84,6 @@ enum STREAM_TYPE {
     void *context;                                                      \
     const char *codecname;                                              \
     char *lang;   /* track language */                                  \
-    char *title;  /* track title */                                     \
-    bool default_track;                                                 \
 
 typedef struct sh_common {
     SH_COMMON