[FFmpeg-devel] [PATCH 01/10] lavu: add av_fourcc_make_string() and av_4cc2str()

Clément Bœsch u at pkh.me
Mon Mar 27 10:51:54 EEST 2017


---
 doc/APIchanges      |  4 ++++
 libavutil/avutil.h  | 14 ++++++++++++++
 libavutil/utils.c   | 21 +++++++++++++++++++++
 libavutil/version.h |  2 +-
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index 6aaa9adceb..4736e3e6fc 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,10 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2017-03-xx - xxxxxxx - lavu 55.52.100 - avutil.h
+  add av_fourcc_make_string() function and av_4cc2str() macro to replace
+  av_get_codec_tag_string() from lavc.
+
 2017-03-xx - xxxxxxx - lavc 57.85.101 - avcodec.h
   vdpau hardware accelerated decoding now supports the new hwaccel API, which
   can create the decoder context and allocate hardware frame automatically.
diff --git a/libavutil/avutil.h b/libavutil/avutil.h
index e9aaa03722..98100fdcc5 100644
--- a/libavutil/avutil.h
+++ b/libavutil/avutil.h
@@ -343,6 +343,20 @@ FILE *av_fopen_utf8(const char *path, const char *mode);
  */
 AVRational av_get_time_base_q(void);
 
+#define AV_FOURCC_MAX_STRING_SIZE 32
+
+#define av_4cc2str(fourcc) av_fourcc_make_string((char[AV_FOURCC_MAX_STRING_SIZE]){0}, fourcc)
+
+/**
+ * Fill the provided buffer with a string containing a FourCC (four-character
+ * code) representation.
+ *
+ * @param buf    a buffer with size in bytes of at least AV_FOURCC_MAX_STRING_SIZE
+ * @param fourcc the fourcc to represent
+ * @return the buffer in input
+ */
+char *av_fourcc_make_string(char *buf, uint32_t fourcc);
+
 /**
  * @}
  * @}
diff --git a/libavutil/utils.c b/libavutil/utils.c
index 36e4dd5fdb..ba557b9252 100644
--- a/libavutil/utils.c
+++ b/libavutil/utils.c
@@ -121,6 +121,27 @@ unsigned av_int_list_length_for_size(unsigned elsize,
     return i;
 }
 
+char *av_fourcc_make_string(char *buf, uint32_t fourcc)
+{
+    int i, len;
+    char *orig_buf = buf;
+    size_t buf_size = AV_FOURCC_MAX_STRING_SIZE;
+
+#define TAG_PRINT(x)                                              \
+    (((x) >= '0' && (x) <= '9') ||                                \
+     ((x) >= 'a' && (x) <= 'z') || ((x) >= 'A' && (x) <= 'Z') ||  \
+     ((x) == '.' || (x) == ' ' || (x) == '-' || (x) == '_'))
+
+    for (i = 0; i < 4; i++) {
+        len = snprintf(buf, buf_size,
+                       TAG_PRINT(fourcc & 0xFF) ? "%c" : "[%d]", fourcc & 0xFF);
+        buf       += len;
+        buf_size   = buf_size > len ? buf_size - len : 0;
+        fourcc   >>= 8;
+    }
+    return orig_buf;
+}
+
 AVRational av_get_time_base_q(void)
 {
     return (AVRational){1, AV_TIME_BASE};
diff --git a/libavutil/version.h b/libavutil/version.h
index 3c86c26638..d6d78e7dc2 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  55
-#define LIBAVUTIL_VERSION_MINOR  51
+#define LIBAVUTIL_VERSION_MINOR  52
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
-- 
2.12.0



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