Merge pull request ocaml-community#16 from LemonBoy/pixfmt

Add Pixel_format.{of_string,to_string,planes}

src/avutil.ml

@@ -26,7 +26,10 @@ let () =
 module Pixel_format = struct
   type t = Pixel_format.t
 
-  external bits : t -> int = "ocaml_avutil_bits_per_pixel"
+  external bits : t -> int = "ocaml_avutil_pixelformat_bits_per_pixel"
+  external planes : t -> int = "ocaml_avutil_pixelformat_planes"
+  external to_string : t -> string = "ocaml_avutil_pixelformat_to_string"
+  external of_string : string -> t = "ocaml_avutil_pixelformat_of_string"
 
   let bits (*?(padding=true)*) p =
     let n = bits p in

src/avutil.mli

@@ -83,6 +83,15 @@ module Pixel_format : sig
 
   (** Return the number of bits of the pixel format. *)
   val bits : (*?padding:bool ->*) t -> int
+
+  (** Return the number of planes of the pixel format. *)
+  val planes : t -> int
+
+  (** [Pixel_format.to_string f] Return a string representation of the pixel format [f]. *)
+  val to_string : t -> string
+
+  (** [Pixel_format.of_string s] Convert the string [s] into a [Pixel_format.t]. @raise Failure if [s] is not a valid format. *)
+  val of_string : string -> t
 end
 
 module Video : sig

src/avutil_stubs.c

@@ -7,9 +7,11 @@
 #include <caml/bigarray.h>
 #include <caml/threads.h>
 
+#include <assert.h>
+
 #include <libavutil/pixfmt.h>
 #include <libavutil/pixdesc.h>
-#include "libavutil/avstring.h"
+#include <libavutil/avstring.h>
 
 #include "avutil_stubs.h"
 #include "pixel_format_stubs.h"
@@ -19,17 +21,41 @@
 char ocaml_av_error_msg[ERROR_MSG_SIZE + 1];
 char ocaml_av_exn_msg[ERROR_MSG_SIZE + 1];
 
-CAMLprim value ocaml_avutil_bits_per_pixel(value pixel)
+CAMLprim value ocaml_avutil_pixelformat_bits_per_pixel(value pixel)
+{
+  CAMLparam1(pixel);
+  enum AVPixelFormat p = PixelFormat_val(pixel);
+
+  CAMLreturn(Val_int(av_get_bits_per_pixel(av_pix_fmt_desc_get(p))));
+}
+
+CAMLprim value ocaml_avutil_pixelformat_planes(value pixel)
 {
   CAMLparam1(pixel);
   enum AVPixelFormat p = PixelFormat_val(pixel);
-  int ans;
 
-  ans = av_get_bits_per_pixel(av_pix_fmt_desc_get(p));
+  CAMLreturn(Val_int(av_pix_fmt_count_planes(p)));
+}
+
+CAMLprim value ocaml_avutil_pixelformat_to_string(value pixel)
+{
+  CAMLparam1(pixel);
+  enum AVPixelFormat p = PixelFormat_val(pixel);
 
-  CAMLreturn(Val_int(ans));
+  CAMLreturn(caml_copy_string(av_get_pix_fmt_name(p)));
 }
 
+CAMLprim value ocaml_avutil_pixelformat_of_string(value name)
+{
+  CAMLparam1(name);
+  enum AVPixelFormat p;
+
+  p = av_get_pix_fmt(String_val(name));
+  if (p != AV_PIX_FMT_NONE)
+      CAMLreturn(Val_PixelFormat(p));
+
+  Raise(EXN_FAILURE, "Invalid format name");
+}
 
 /**** Time format ****/
 int64_t second_fractions_of_time_format(value time_format)