avformat/webm_chunk: Don't copy header filename

Instead just reuse the filename string that is given via an option
for the child muxer's url field.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavformat/webm_chunk.c

@@ -65,6 +65,11 @@ static int chunk_mux_init(AVFormatContext *s)
     AVDictionary *dict = NULL;
     int ret;
 
+    if (!wc->header_filename) {
+        av_log(s, AV_LOG_ERROR, "No header filename provided\n");
+        return AVERROR(EINVAL);
+    }
+
     oformat = av_guess_format("webm", s->url, "video/webm");
     if (!oformat)
         return AVERROR_MUXER_NOT_FOUND;
@@ -74,6 +79,9 @@ static int chunk_mux_init(AVFormatContext *s)
         return ret;
     oc = wc->avf;
 
+    ff_format_set_url(oc, wc->header_filename);
+    wc->header_filename = NULL;
+
     oc->interrupt_callback = s->interrupt_callback;
     oc->max_delay          = s->max_delay;
     oc->flags                 = s->flags & ~AVFMT_FLAG_FLUSH_PACKETS;
@@ -120,30 +128,17 @@ static int chunk_mux_init(AVFormatContext *s)
     return 0;
 }
 
-static int get_chunk_filename(AVFormatContext *s, int is_header, char filename[MAX_FILENAME_SIZE])
+static int get_chunk_filename(AVFormatContext *s, char filename[MAX_FILENAME_SIZE])
 {
     WebMChunkContext *wc = s->priv_data;
     if (!filename) {
         return AVERROR(EINVAL);
     }
-    if (is_header) {
-        int len;
-        if (!wc->header_filename) {
-            av_log(s, AV_LOG_ERROR, "No header filename provided\n");
-            return AVERROR(EINVAL);
-        }
-        len = av_strlcpy(filename, wc->header_filename, MAX_FILENAME_SIZE);
-        if (len >= MAX_FILENAME_SIZE) {
-            av_log(s, AV_LOG_ERROR, "Header filename too long\n");
-            return AVERROR(EINVAL);
-        }
-    } else {
         if (av_get_frame_filename(filename, MAX_FILENAME_SIZE,
                                   s->url, wc->chunk_index - 1) < 0) {
             av_log(s, AV_LOG_ERROR, "Invalid chunk filename template '%s'\n", s->url);
             return AVERROR(EINVAL);
         }
-    }
     return 0;
 }
 
@@ -153,8 +148,6 @@ static int webm_chunk_write_header(AVFormatContext *s)
     AVFormatContext *oc = NULL;
     int ret;
     AVDictionary *options = NULL;
-    char oc_filename[MAX_FILENAME_SIZE];
-    char *oc_url;
 
     // DASH Streams can only have either one track per file.
     if (s->nb_streams != 1) { return AVERROR_INVALIDDATA; }
@@ -166,13 +159,6 @@ static int webm_chunk_write_header(AVFormatContext *s)
     if (ret < 0)
         return ret;
     oc = wc->avf;
-    ret = get_chunk_filename(s, 1, oc_filename);
-    if (ret < 0)
-        return ret;
-    oc_url = av_strdup(oc_filename);
-    if (!oc_url)
-        return AVERROR(ENOMEM);
-    ff_format_set_url(oc, oc_url);
     if (wc->http_method)
         av_dict_set(&options, "method", wc->http_method, 0);
     ret = s->io_open(s, &oc->pb, oc->url, AVIO_FLAG_WRITE, &options);
@@ -220,7 +206,7 @@ static int chunk_end(AVFormatContext *s, int flush)
         av_write_frame(oc, NULL);
     buffer_size = avio_close_dyn_buf(oc->pb, &buffer);
     oc->pb = NULL;
-    ret = get_chunk_filename(s, 0, filename);
+    ret = get_chunk_filename(s, filename);
     if (ret < 0)
         goto fail;
     if (wc->http_method)