[FFmpeg-devel] [PATCH 4/5] lavf/dashdec: improve memory handling

[rcombs]

- Fixes a couple leaks
- Adds an av_freep equivalent for libxml buffers
- Avoids some redundant copying
---
 libavformat/dashdec.c | 44 +++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
index c94ce2caca..378c892b87 100644
--- a/libavformat/dashdec.c
+++ b/libavformat/dashdec.c
@@ -147,9 +147,6 @@ typedef struct DASHContext {
     uint64_t period_duration;
     uint64_t period_start;
 
-    /* AdaptationSet Attribute */
-    char *adaptationset_lang;
-
     int is_live;
     AVIOInterruptCB *interrupt_callback;
     char *allowed_extensions;
@@ -162,6 +159,15 @@ typedef struct DASHContext {
 
 } DASHContext;
 
+static void xml_freep(void* arg)
+{
+    void *val;
+
+    memcpy(&val, arg, sizeof(val));
+    memcpy(arg, &(void *){ NULL }, sizeof(val));
+    xmlFree(val);
+}
+
 static int ishttp(char *url)
 {
     const char *proto_name = avio_find_protocol_name(url);
@@ -362,6 +368,8 @@ static void free_representation(struct representation *pls)
         avformat_close_input(&pls->ctx);
     }
 
+    xml_freep(&pls->lang);
+
     av_freep(&pls->url_template);
     av_freep(&pls);
 }
@@ -878,15 +886,9 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
             ret = AVERROR(ENOMEM);
             goto end;
         }
-        if (c->adaptationset_lang) {
-            rep->lang = av_strdup(c->adaptationset_lang);
-            if (!rep->lang) {
-                av_log(s, AV_LOG_ERROR, "alloc language memory failure\n");
-                av_freep(&rep);
-                ret = AVERROR(ENOMEM);
-                goto end;
-            }
-        }
+
+        rep->lang = xmlGetProp(adaptationset_node, "lang");
+
         rep->parent = s;
         representation_segmenttemplate_node = find_child_node_by_name(representation_node, "SegmentTemplate");
         representation_baseurl_node = find_child_node_by_name(representation_node, "BaseURL");
@@ -965,7 +967,8 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
                 xmlFree(startnumber_val);
             }
             if (adaptationset_supplementalproperty_node) {
-                if (!av_strcasecmp(xmlGetProp(adaptationset_supplementalproperty_node,"schemeIdUri"), "http://dashif.org/guidelines/last-segment-number")) {
+                char *schemeIdUri = xmlGetProp(adaptationset_supplementalproperty_node, "schemeIdUri");
+                if (!av_strcasecmp(schemeIdUri, "http://dashif.org/guidelines/last-segment-number")) {
                     val = xmlGetProp(adaptationset_supplementalproperty_node,"value");
                     if (!val) {
                         av_log(s, AV_LOG_ERROR, "Missing value attribute in adaptationset_supplementalproperty_node\n");
@@ -974,6 +977,7 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
                         xmlFree(val);
                     }
                 }
+                xmlFree(schemeIdUri);
             }
 
             fragment_timeline_node = find_child_node_by_name(representation_segmenttemplate_node, "SegmentTimeline");
@@ -1120,13 +1124,10 @@ end:
 
 static int parse_manifest_adaptationset_attr(AVFormatContext *s, xmlNodePtr adaptationset_node)
 {
-    DASHContext *c = s->priv_data;
-
     if (!adaptationset_node) {
         av_log(s, AV_LOG_WARNING, "Cannot get AdaptationSet\n");
         return AVERROR(EINVAL);
     }
-    c->adaptationset_lang = xmlGetProp(adaptationset_node, "lang");
 
     return 0;
 }
@@ -1139,7 +1140,6 @@ static int parse_manifest_adaptationset(AVFormatContext *s, const char *url,
                                         xmlNodePtr period_segmentlist_node)
 {
     int ret = 0;
-    DASHContext *c = s->priv_data;
     xmlNodePtr fragment_template_node = NULL;
     xmlNodePtr content_component_node = NULL;
     xmlNodePtr adaptationset_baseurl_node = NULL;
@@ -1182,7 +1182,6 @@ static int parse_manifest_adaptationset(AVFormatContext *s, const char *url,
     }
 
 err:
-    av_freep(&c->adaptationset_lang);
     return ret;
 }
 
@@ -2157,6 +2156,10 @@ static int dash_read_header(AVFormatContext *s)
                 av_dict_set_int(&rep->assoc_stream->metadata, "variant_bitrate", rep->bandwidth, 0);
             if (rep->id[0])
                 av_dict_set(&rep->assoc_stream->metadata, "id", rep->id, 0);
+            if (rep->lang) {
+                av_dict_set(&rep->assoc_stream->metadata, "language", rep->lang, 0);
+                xml_freep(&rep->lang);
+            }
         }
         for (i = 0; i < c->n_audios; i++) {
             rep = c->audios[i];
@@ -2168,7 +2171,7 @@ static int dash_read_header(AVFormatContext *s)
                 av_dict_set(&rep->assoc_stream->metadata, "id", rep->id, 0);
             if (rep->lang) {
                 av_dict_set(&rep->assoc_stream->metadata, "language", rep->lang, 0);
-                av_freep(&rep->lang);
+                xml_freep(&rep->lang);
             }
         }
         for (i = 0; i < c->n_subtitles; i++) {
@@ -2179,7 +2182,7 @@ static int dash_read_header(AVFormatContext *s)
                 av_dict_set(&rep->assoc_stream->metadata, "id", rep->id, 0);
             if (rep->lang) {
                 av_dict_set(&rep->assoc_stream->metadata, "language", rep->lang, 0);
-                av_freep(&rep->lang);
+                xml_freep(&rep->lang);
             }
         }
     }
@@ -2282,6 +2285,7 @@ static int dash_close(AVFormatContext *s)
     DASHContext *c = s->priv_data;
     free_audio_list(c);
     free_video_list(c);
+    free_subtitle_list(c);
     av_dict_free(&c->avio_opts);
     av_freep(&c->base_url);
     return 0;
-- 
2.26.2