avformat/rpl: Allow a file to have audio, but not video

Signed-off-by: Cameron Cawley <ccawley2011@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/rpl.c

@@ -124,7 +124,7 @@ static int rpl_read_header(AVFormatContext *s)
 
     uint32_t i;
 
-    int32_t audio_format, chunk_catalog_offset, number_of_chunks;
+    int32_t video_format, audio_format, chunk_catalog_offset, number_of_chunks;
     AVRational fps;
 
     char line[RPL_LINE_LENGTH];
@@ -144,17 +144,16 @@ static int rpl_read_header(AVFormatContext *s)
     av_dict_set(&s->metadata, "author"   , line, 0);
 
     // video headers
+    video_format = read_line_and_int(pb, &error);
+    if (video_format) {
         vst = avformat_new_stream(s, NULL);
         if (!vst)
             return AVERROR(ENOMEM);
         vst->codecpar->codec_type      = AVMEDIA_TYPE_VIDEO;
-    vst->codecpar->codec_tag       = read_line_and_int(pb, &error);  // video format
+        vst->codecpar->codec_tag       = video_format;
         vst->codecpar->width           = read_line_and_int(pb, &error);  // video width
         vst->codecpar->height          = read_line_and_int(pb, &error);  // video height
         vst->codecpar->bits_per_coded_sample = read_line_and_int(pb, &error);  // video bits per sample
-    error |= read_line(pb, line, sizeof(line));                   // video frames per second
-    fps = read_fps(line, &error);
-    avpriv_set_pts_info(vst, 32, fps.den, fps.num);
 
         // Figure out the video codec
         switch (vst->codecpar->codec_tag) {
@@ -176,6 +175,15 @@ static int rpl_read_header(AVFormatContext *s)
                                               av_fourcc2str(vst->codecpar->codec_tag));
                 vst->codecpar->codec_id = AV_CODEC_ID_NONE;
         }
+    } else {
+        for (i = 0; i < 3; i++)
+            error |= read_line(pb, line, sizeof(line));
+    }
+
+    error |= read_line(pb, line, sizeof(line));                   // video frames per second
+    fps = read_fps(line, &error);
+    if (vst)
+        avpriv_set_pts_info(vst, 32, fps.den, fps.num);
 
     // Audio headers
 
@@ -246,7 +254,7 @@ static int rpl_read_header(AVFormatContext *s)
     }
 
     rpl->frames_per_chunk = read_line_and_int(pb, &error);  // video frames per chunk
-    if (rpl->frames_per_chunk > 1 && vst->codecpar->codec_tag != 124)
+    if (vst && rpl->frames_per_chunk > 1 && vst->codecpar->codec_tag != 124)
         av_log(s, AV_LOG_WARNING,
                "Don't know how to split frames for video format %s. "
                "Video stream will be broken!\n", av_fourcc2str(vst->codecpar->codec_tag));
@@ -261,6 +269,7 @@ static int rpl_read_header(AVFormatContext *s)
         read_line_and_int(pb, &error);           //   (file index)
     error |= read_line(pb, line, sizeof(line));  // offset to "helpful" sprite
     error |= read_line(pb, line, sizeof(line));  // size of "helpful" sprite
+    if (vst)
         error |= read_line(pb, line, sizeof(line));  // offset to key frame list
 
     // Read the index
@@ -274,6 +283,7 @@ static int rpl_read_header(AVFormatContext *s)
             error = -1;
             continue;
         }
+        if (vst)
             av_add_index_entry(vst, offset, i * rpl->frames_per_chunk,
                                video_size, rpl->frames_per_chunk, 0);
         if (ast)