[03/12] libavformat: Add a flag for muxers that support write_packet(NULL) for flushing

Message ID 1327098137-16251-1-git-send-email-martin@martin.st
State Committed
Commit f1caf01d5e2913a96c5689e6570fd10e25d1c76b
Headers show

Commit Message

Martin Storsjö Jan. 20, 2012, 10:22 p.m.
---
Wrote a bit more explanations in the doxy, as requested by Justin
and Anton on irc.

 libavformat/avformat.h |   18 +++++++++++++++---
 libavformat/utils.c    |   10 +++++++++-
 libavformat/version.h  |    2 +-
 3 files changed, 25 insertions(+), 5 deletions(-)

Comments

Justin Ruggles Jan. 23, 2012, 2:50 p.m. | #1
On 01/20/2012 05:22 PM, Martin Storsjö wrote:

> ---
> Wrote a bit more explanations in the doxy, as requested by Justin
> and Anton on irc.


patch looks ok to me.

-Justin

Patch

diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 71aed80..18a80ac 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -380,6 +380,7 @@  typedef struct AVFormatParameters {
 #define AVFMT_NOBINSEARCH   0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
 #define AVFMT_NOGENSEARCH   0x4000 /**< Format does not allow to fallback to generic search */
 #define AVFMT_NO_BYTE_SEEK  0x8000 /**< Format does not allow seeking by bytes */
+#define AVFMT_ALLOW_FLUSH  0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
 
 /**
  * @addtogroup lavf_encoding
@@ -403,12 +404,19 @@  typedef struct AVOutputFormat {
     enum CodecID audio_codec; /**< default audio codec */
     enum CodecID video_codec; /**< default video codec */
     int (*write_header)(struct AVFormatContext *);
+    /**
+     * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
+     * pkt can be NULL in order to flush data buffered in the muxer.
+     * When flushing, return 0 if there still is more data to flush,
+     * or 1 if everything was flushed and there is no more buffered
+     * data.
+     */
     int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
     int (*write_trailer)(struct AVFormatContext *);
     /**
      * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
      * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
-     * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS
+     * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH
      */
     int flags;
     /**
@@ -1685,8 +1693,12 @@  attribute_deprecated int av_write_header(AVFormatContext *s);
  *
  * @param s media file handle
  * @param pkt The packet, which contains the stream_index, buf/buf_size,
-              dts/pts, ...
- * @return < 0 on error, = 0 if OK, 1 if end of stream wanted
+ *            dts/pts, ...
+ *            This can be NULL (at any time, not just at the end), in
+ *            order to immediately flush data buffered within the muxer,
+ *            for muxers that buffer up data internally before writing it
+ *            to the output.
+ * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
  */
 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
 
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 22ee13b..093389b 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -3135,7 +3135,15 @@  static int compute_pkt_fields2(AVFormatContext *s, AVStream *st, AVPacket *pkt){
 
 int av_write_frame(AVFormatContext *s, AVPacket *pkt)
 {
-    int ret = compute_pkt_fields2(s, s->streams[pkt->stream_index], pkt);
+    int ret;
+
+    if (!pkt) {
+        if (s->oformat->flags & AVFMT_ALLOW_FLUSH)
+            return s->oformat->write_packet(s, pkt);
+        return 1;
+    }
+
+    ret = compute_pkt_fields2(s, s->streams[pkt->stream_index], pkt);
 
     if(ret<0 && !(s->oformat->flags & AVFMT_NOTIMESTAMPS))
         return ret;
diff --git a/libavformat/version.h b/libavformat/version.h
index 009a60b..898f4b1 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@ 
 #include "libavutil/avutil.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 53
-#define LIBAVFORMAT_VERSION_MINOR 21
+#define LIBAVFORMAT_VERSION_MINOR 22
 #define LIBAVFORMAT_VERSION_MICRO  0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \