Compared to ad-hoc if(printed) ... code this allows the user to disable
it by adjusting the log level
TODO: APIChanges & version bump
Signed-off-by: Michael Niedermayer <michael(a)niedermayer.cc>
---
libavutil/log.c | 9 +++++++++
libavutil/log.h | 21 +++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/libavutil/log.c b/libavutil/log.c
index 0a7b169bc0..57301d42d6 100644
--- a/libavutil/log.c
+++ b/libavutil/log.c
@@ -368,6 +368,15 @@ void av_log(void* avcl, int level, const char *fmt, ...)
va_end(vl);
}
+void av_log_once(void* avcl, int initial_level, int subsequent_level, int *state, const char *fmt, ...)
+{
+ va_list vl;
+ va_start(vl, fmt);
+ av_vlog(avcl, *state ? subsequent_level : initial_level, fmt, vl);
+ va_end(vl);
+ *state = 1;
+}
+
void av_vlog(void* avcl, int level, const char *fmt, va_list vl)
{
AVClass* avc = avcl ? *(AVClass **) avcl : NULL;
diff --git a/libavutil/log.h b/libavutil/log.h
index d9554e609d..9c14188a9c 100644
--- a/libavutil/log.h
+++ b/libavutil/log.h
@@ -233,6 +233,27 @@ typedef struct AVClass {
*/
void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
+/**
+ * Send the specified message to the log once with the initial_level and then with
+ * the subsequent_level. By default, all logging messages are sent to
+ * stderr. This behavior can be altered by setting a different logging callback
+ * function.
+ * @see av_log
+ *
+ * @param avcl A pointer to an arbitrary struct of which the first field is a
+ * pointer to an AVClass struct or NULL if general log.
+ * @param initial_level importance level of the message expressed using a @ref
+ * lavu_log_constants "Logging Constant" for the first occurance.
+ * @param subsequent_level importance level of the message expressed using a @ref
+ * lavu_log_constants "Logging Constant" after the first occurance.
+ * @param fmt The format string (printf-compatible) that specifies how
+ * subsequent arguments are converted to output.
+ * @param state a variable to keep trak of if a message has already been printed
+ * this must be initialized to 0 before the first use. The same state
+ * must not be accessed by 2 Threads simultaneously.
+ */
+void av_log_once(void* avcl, int initial_level, int subsequent_level, int *state, const char *fmt, ...) av_printf_format(5, 6);
+
/**
* Send the specified message to the log if the level is less than or equal
--
2.17.1
