From: Jan Sebechlebsky <sebechlebsky...@gmail.com>
Add comments regarding AVFMG_FLAG_NONBLOCK usage with muxers.
Add assert forbiding use of nonblocking muxer with
av_interleaved_write_frame.
Signed-off-by: Jan Sebechlebsky <sebechlebsky...@gmail.com>
---
Changes since the last version of the patch:
- added assert to the beginning of av_interleaved_write_frame ensuring
it is not called with muxer in nonblocking mode.
- Changed commit description.
libavformat/avformat.h | 9 ++++++++-
libavformat/mux.c | 2 ++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 83903b5..79c2511 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1428,7 +1428,7 @@ typedef struct AVFormatContext {
int flags;
#define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it
requires parsing future frames.
#define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
-#define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets
from input.
+#define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets
from input / writing packets to output.
#define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain
both DTS & PTS
#define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other
values, just return what is stored in the container
#define AVFMT_FLAG_NOPARSE 0x0020 ///< Do not use AVParsers, you also
must set AVFMT_FLAG_NOFILLIN as the fillin code works on frames and no parsing
-> no frames. Also seeking to frames can not work if parsing to find frame
boundaries has been disabled
@@ -2391,6 +2391,10 @@ int avformat_write_header(AVFormatContext *s,
AVDictionary **options);
* the interleaving should call av_interleaved_write_frame() instead of this
* function.
*
+ * In case the muxer is operating in non-blocking mode (AVFMT_FLAG_NONBLOCK
+ * is set), this function can return AVERROR(EAGAIN) meaning the call should
+ * be repeated.
+ *
* @param s media file handle
* @param pkt The packet containing the data to be written. Note that unlike
* av_interleaved_write_frame(), this function does not take
@@ -2433,6 +2437,9 @@ int av_write_frame(AVFormatContext *s, AVPacket *pkt);
* knowledge of future packets, improving e.g. the behaviour of the mp4
* muxer for VFR content in fragmenting mode.
*
+ * This call is not supported and must not be called if muxer is operating
+ * in non-blocking mode (AVFMT_FLAG_NONBLOCK is set).
+ *
* @param s media file handle
* @param pkt The packet containing the data to be written.
* <br>
diff --git a/libavformat/mux.c b/libavformat/mux.c
index 0f002a3..b4698b7 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -1139,6 +1139,8 @@ int av_interleaved_write_frame(AVFormatContext *s,
AVPacket *pkt)
{
int ret, flush = 0;
+ av_assert0(!(s->flags & AVFMT_FLAG_NONBLOCK));
+
ret = prepare_input_packet(s, pkt);
if (ret < 0)
goto fail;
--
1.9.1
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