[FFmpeg-devel] [RFC] missing close/free functions for avformat?

[Reimar Döffinger]

Hello,
On Mon, Dec 17, 2007 at 01:09:14PM +0100, Michael Niedermayer wrote:
> On Sun, Dec 16, 2007 at 11:09:48AM +0100, Reimar D?ffinger wrote:
> > On Sun, Dec 16, 2007 at 02:44:09AM +0100, Michael Niedermayer wrote:
> > > On Sat, Dec 15, 2007 at 08:32:53PM +0100, Reimar D?ffinger wrote:
> > [...]
> > > > It's untested, but does something like this look good?
> > > 
> > > if you test it and are sure its correct and theres no way to make
> > > av_close_input_file() work with _stream as well ...
> > 
> > Of course there are ways, e.g. a autoalloced_byteio flag (ok, preferably
> > a better name) in the AVFormatContext that indicates if we should do
> > url_fclose on the byteiocontext or not.
> > That would mean we could get rid of the (very minor) "must_open_file"
> > code duplication between open and close functions.
> > But then IMO the naming is inconsistent, and calling it
> > av_free_format_context would be better (keeping the av_close_input_file
> > as deprecated for compatibility).
> > I find that name appropriate because such a function frees the
> > AVFormatContext and everything that avformat allocated "behind the back"
> > of the user, and the only alternative that would give a consistent
> 
> ok

This is what I had in mind, say if you think it makes sense.

Greetings,
Reimar D?ffinger
-------------- next part --------------
Index: libavformat/utils.c
===================================================================
--- libavformat/utils.c	(revision 11254)
+++ libavformat/utils.c	(working copy)
@@ -477,6 +474,8 @@
         }
     }
     err = av_open_input_stream(ic_ptr, pb, filename, fmt, ap);
+    if (pb)
+        (*ic_ptr)->fclose_byteio = 1;
     if (err)
         goto fail;
     return 0;
@@ -2039,7 +2038,7 @@
     return AVERROR(ENOSYS);
 }
 
-void av_close_input_file(AVFormatContext *s)
+void av_free_format_context(AVFormatContext *s)
 {
     int i;
     AVStream *st;
@@ -2068,12 +2067,17 @@
         av_freep(&s->programs[i]);
     }
     flush_packet_queue(s);
-    if (!(s->iformat->flags & AVFMT_NOFILE))
+    if (s->fclose_byteio)
         url_fclose(s->pb);
     av_freep(&s->priv_data);
     av_free(s);
 }
 
+void av_close_input_file(AVFormatContext *s)
+{
+    av_free_format_context(s);
+}
+
 AVStream *av_new_stream(AVFormatContext *s, int id)
 {
     AVStream *st;
Index: libavformat/avformat.h
===================================================================
--- libavformat/avformat.h	(revision 11254)
+++ libavformat/avformat.h	(working copy)
@@ -21,8 +21,8 @@
 #ifndef FFMPEG_AVFORMAT_H
 #define FFMPEG_AVFORMAT_H
 
-#define LIBAVFORMAT_VERSION_INT ((52<<16)+(2<<8)+0)
-#define LIBAVFORMAT_VERSION     52.2.0
+#define LIBAVFORMAT_VERSION_INT ((52<<16)+(3<<8)+0)
+#define LIBAVFORMAT_VERSION     52.3.0
 #define LIBAVFORMAT_BUILD       LIBAVFORMAT_VERSION_INT
 
 #define LIBAVFORMAT_IDENT       "Lavf" AV_STRINGIFY(LIBAVFORMAT_VERSION)
@@ -445,6 +434,14 @@
 
     unsigned int nb_programs;
     AVProgram **programs;
+
+    /**
+     * If true, url_fclose will be called on the ByteIOContext
+     * otherwise the user is responsible for freeing it.
+     * This is for internal use by libavformat and should not
+     * be accessed by external code.
+     */
+    int fclose_byteio;
 } AVFormatContext;
 
 typedef struct AVPacketList {
@@ -571,12 +568,15 @@
                        AVFormatParameters *ap);
 /**
  * Allocate an AVFormatContext.
- * Can be freed with av_free() but do not forget to free everything you
- * explicitly allocated as well!
  */
 AVFormatContext *av_alloc_format_context(void);
 
 /**
+ * Free an AVFormatContext and all substructures allocated by libavformat.
+ */
+void av_free_format_context(AVFormatContext *);
+
+/**
  * Read packets of a media file to get stream information. This
  * is useful for file formats with no headers such as MPEG. This
  * function also computes the real frame rate in case of mpeg2 repeat
@@ -653,8 +653,9 @@
  * Close a media file (but not its codecs).
  *
  * @param s media file handle
+ * @deprecated Use av_free_format_context instead.
  */
-void av_close_input_file(AVFormatContext *s);
+attribute_deprecated void av_close_input_file(AVFormatContext *s);
 
 /**
  * Add a new stream to a media file.