ffmpeg: Add basic support to mux multiple programs

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/ffmpeg.texi

@@ -355,6 +355,11 @@ To set the language of the first audio stream:
 ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
 @end example
 
+@item -program [title=@var{title}:]st=@var{stream}[:st=@var{stream}...] (@emph{output})
+
+Creates a program with the specified @var{title} and adds the specified
+@var{stream}(s) to it.
+
 @item -target @var{type} (@emph{output})
 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or

ffmpeg.h

@@ -216,6 +216,8 @@ typedef struct OptionsContext {
     int        nb_discard;
     SpecifierOpt *disposition;
     int        nb_disposition;
+    SpecifierOpt *program;
+    int        nb_program;
 } OptionsContext;
 
 typedef struct InputFilter {

ffmpeg_opt.c

@@ -2414,6 +2414,42 @@ loop_end:
         }
     }
 
+    /* process manually set programs */
+    for (i = 0; i < o->nb_program; i++) {
+        const char *p = o->program[i].u.str;
+        int progid = i+1;
+        AVProgram *program = av_new_program(oc, progid);
+
+        while(*p) {
+            const char *p2 = av_get_token(&p, ":");
+            char *key;
+            if (!p2)
+                break;
+            if(*p) p++;
+
+            key = av_get_token(&p2, "=");
+            if (!key) {
+                av_log(NULL, AV_LOG_FATAL,
+                       "No '=' character in program string %s.\n",
+                       p2);
+                exit_program(1);
+            }
+            if (!*p2)
+                exit_program(1);
+            p2++;
+
+            if (!strcmp(key, "title")) {
+                av_dict_set(&program->metadata, "title", p2, 0);
+            } else if (!strcmp(key, "st")) {
+                int st_num = strtol(p2, NULL, 0);
+                av_program_add_stream_index(oc, progid, st_num);
+            } else {
+                av_log(NULL, AV_LOG_FATAL, "Unknown program key %s.\n", key);
+                exit_program(1);
+            }
+        }
+    }
+
     return 0;
 }
 
@@ -3093,6 +3129,8 @@ const OptionDef options[] = {
         "set the recording timestamp ('now' to set the current time)", "time" },
     { "metadata",       HAS_ARG | OPT_STRING | OPT_SPEC | OPT_OUTPUT, { .off = OFFSET(metadata) },
         "add metadata", "string=string" },
+    { "program",        HAS_ARG | OPT_STRING | OPT_SPEC | OPT_OUTPUT, { .off = OFFSET(program) },
+        "add program with specified streams", "title=string:st=number..." },
     { "dframes",        HAS_ARG | OPT_PERFILE | OPT_EXPERT |
                         OPT_OUTPUT,                                  { .func_arg = opt_data_frames },
         "set the number of data frames to output", "number" },