avfilter/src_movie: add various commands

add seek command
add get_duration command

Update to codecpar by commiter
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/filters.texi

@@ -16976,4 +16976,28 @@ movie=dvd.vob:s=v:0+#0x81 [video] [audio]
 @end example
 @end itemize
 
+@subsection Commands
+
+Both movie and amovie support the following commands:
+@table @option
+@item seek
+Perform seek using "av_seek_frame".
+The syntax is: seek @var{stream_index}|@var{timestamp}|@var{flags}
+@itemize
+@item
+@var{stream_index}: If stream_index is -1, a default
+stream is selected, and @var{timestamp} is automatically converted
+from AV_TIME_BASE units to the stream specific time_base.
+@item
+@var{timestamp}: Timestamp in AVStream.time_base units
+or, if no stream is specified, in AV_TIME_BASE units.
+@item
+@var{flags}: Flags which select direction and seeking mode.
+@end itemize
+
+@item get_duration
+Get movie duration in AV_TIME_BASE units.
+
+@end table
+
 @c man end MULTIMEDIA SOURCES

libavfilter/src_movie.c

@@ -582,6 +582,49 @@ static int movie_request_frame(AVFilterLink *outlink)
     }
 }
 
+static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
+                           char *res, int res_len, int flags)
+{
+    MovieContext *movie = ctx->priv;
+    int ret = AVERROR(ENOSYS);
+
+    if (!strcmp(cmd, "seek")) {
+        int idx, flags, i;
+        int64_t ts;
+        char tail[2];
+
+        if (sscanf(args, "%i|%"SCNi64"|%i %1s", &idx, &ts, &flags, tail) != 3)
+            return AVERROR(EINVAL);
+
+        ret = av_seek_frame(movie->format_ctx, idx, ts, flags);
+        if (ret < 0)
+            return ret;
+
+        for (i = 0; i < ctx->nb_outputs; i++) {
+            avcodec_flush_buffers(movie->st[i].codec_ctx);
+            movie->st[i].done = 0;
+        }
+        return ret;
+    } else if (!strcmp(cmd, "get_duration")) {
+        int print_len;
+        char tail[2];
+
+        if (!res || res_len <= 0)
+            return AVERROR(EINVAL);
+
+        if (args && sscanf(args, "%1s", tail) == 1)
+            return AVERROR(EINVAL);
+
+        print_len = snprintf(res, res_len, "%"PRId64, movie->format_ctx->duration);
+        if (print_len < 0 || print_len >= res_len)
+            return AVERROR(EINVAL);
+
+        return 0;
+    }
+
+    return ret;
+}
+
 #if CONFIG_MOVIE_FILTER
 
 AVFILTER_DEFINE_CLASS(movie);
@@ -598,6 +641,7 @@ AVFilter ff_avsrc_movie = {
     .inputs    = NULL,
     .outputs   = NULL,
     .flags     = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
+    .process_command = process_command
 };
 
 #endif  /* CONFIG_MOVIE_FILTER */
@@ -619,6 +663,7 @@ AVFilter ff_avsrc_amovie = {
     .outputs    = NULL,
     .priv_class = &amovie_class,
     .flags      = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
+    .process_command = process_command,
 };
 
 #endif /* CONFIG_AMOVIE_FILTER */