Added packed big array API (#68)

CHANGES

@@ -1,3 +1,9 @@
+1.2.1 (unreleased)
+======
+* Fixed plane size when allocating big array planes in `swscale`.
+* Added packed big array API to `swscale` where all planes are alloacted in
+  on contiguous memory region.
+
 1.2.0 (2024-09-24)
 =====
 * Removed unused `Av.write_audio_frame`/`Av.write_video_frame`.

dune-project

@@ -1,7 +1,7 @@
 (lang dune 3.6)
 
 (name ffmpeg)
-(version 1.2.0)
+(version 1.2.1)
 (source (github savonet/ocaml-ffmpeg))
 (license LGPL-2.1-only)
 (authors "The Savonet Team <[email protected]>")

ffmpeg-av.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg libraries -- top-level helpers"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg-avcodec.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg avcodec library"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg-avdevice.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg avdevice library"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg-avfilter.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg avfilter library"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg-avutil.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg avutil libraries"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg-swresample.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg swresample library"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg-swscale.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg swscale library"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

ffmpeg.opam

@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "1.2.0"
+version: "1.2.1"
 synopsis: "Bindings for the ffmpeg libraries"
 maintainer: ["Romain Beauxis <[email protected]>"]
 authors: ["The Savonet Team <[email protected]>"]

swscale/swscale.ml

@@ -20,7 +20,7 @@ type planes = (data * int) array
 external scale : t -> planes -> int -> int -> planes -> int -> unit
   = "ocaml_swscale_scale_byte" "ocaml_swscale_scale"
 
-type vector_kind = Ba | Frm | Str
+type vector_kind = PackedBa | Ba | Frm | Str
 
 module type VideoData = sig
   type t
@@ -34,6 +34,13 @@ module BigArray = struct
   let vk = Ba
 end
 
+module PackedBigArray = struct
+  type plane = { plane_size : int; stride : int }
+  type t = { data : data; planes : plane array }
+
+  let vk = PackedBa
+end
+
 module Frame = struct
   type t = video frame
 

swscale/swscale.mli

@@ -27,7 +27,7 @@ val scale : t -> planes -> int -> int -> planes -> int -> unit
 
 (**/**)
 
-type vector_kind = Ba | Frm | Str
+type vector_kind = PackedBa | Ba | Frm | Str
 
 (**/**)
 
@@ -68,13 +68,21 @@ module Make (I : VideoData) (O : VideoData) : sig
   val convert : t -> I.t -> O.t
 end
 
-(** Unsigned 8 bit bigarray. *)
+(** Unsigned 8 bit bigarray split by planes. *)
 module BigArray : sig
   type t = planes
 
   val vk : vector_kind
 end
 
+(** Unsigned 8 bit bigarray in a single packed array.. *)
+module PackedBigArray : sig
+  type plane = { plane_size : int; stride : int }
+  type t = { data : data; planes : plane array }
+
+  val vk : vector_kind
+end
+
 (** Video frame. *)
 module Frame : sig
   type t = video frame

swscale/swscale_stubs.c

@@ -158,7 +158,7 @@ CAMLprim value ocaml_swscale_scale_byte(value *argv, int argn) {
 
 /***** Contexts *****/
 
-typedef enum _vector_kind { Ba, Frm, Str } vector_kind;
+typedef enum _vector_kind { PackedBa, Ba, Frm, Str } vector_kind;
 
 struct video_t {
   int width;
@@ -235,6 +235,27 @@ static int get_in_pixels_ba(sws_t *sws, value *in_vector) {
   CAMLreturnT(int, nb_planes);
 }
 
+static int get_in_pixels_packed_ba(sws_t *sws, value *in_vector) {
+  CAMLparam0();
+  CAMLlocal1(v);
+  uint8_t *data = Caml_ba_data_val(Field(*in_vector, 0));
+  int i, nb_planes = Wosize_val(Field(*in_vector, 1));
+  int stride, plane_size, offset = 0;
+
+  for (i = 0; i < nb_planes && i < 4; i++) {
+    v = Field(Field(*in_vector, 1), i);
+    plane_size = Int_val(Field(v, 0));
+    stride = Int_val(Field(v, 1));
+
+    sws->in.slice[i] = data + offset;
+    sws->in.stride[i] = stride;
+
+    offset += plane_size;
+  }
+
+  CAMLreturnT(int, nb_planes);
+}
+
 static int alloc_out_frame(sws_t *sws, value *out_vect, value *tmp) {
   int ret;
   AVFrame *frame = av_frame_alloc();
@@ -325,6 +346,38 @@ static int alloc_out_ba(sws_t *sws, value *out_vect, value *tmp) {
   return 0;
 }
 
+static int alloc_out_packed_ba(sws_t *sws, value *out_vect, value *tmp) {
+  int i, offset = 0;
+  intnat out_size = 0;
+  uint8_t *data;
+
+  for (i = 0; i < sws->out.nb_planes; i++)
+    out_size += sws->out.plane_sizes[i];
+
+  out_size += 16;
+
+  *out_vect = caml_alloc_tuple(2);
+  Store_field(
+      *out_vect, 0,
+      caml_ba_alloc(CAML_BA_C_LAYOUT | CAML_BA_UINT8, 1, NULL, &out_size));
+  Store_field(*out_vect, 1, caml_alloc_tuple(sws->out.nb_planes));
+
+  data = Caml_ba_data_val(Field(*out_vect, 0));
+
+  for (i = 0; i < sws->out.nb_planes; i++) {
+    *tmp = caml_alloc_tuple(2);
+    Store_field(*tmp, 0, Val_int(sws->out.plane_sizes[i]));
+    Store_field(*tmp, 1, Val_int(sws->out.stride[i]));
+
+    Store_field(Field(*out_vect, 1), i, *tmp);
+
+    sws->out.slice[i] = data + offset;
+    offset += sws->out.plane_sizes[i];
+  }
+
+  return 0;
+}
+
 CAMLprim value ocaml_swscale_convert(value _sws, value _in_vector) {
   CAMLparam2(_sws, _in_vector);
   CAMLlocal2(out_vect, tmp);
@@ -436,6 +489,8 @@ CAMLprim value ocaml_swscale_create(value flags_, value in_vector_kind_,
   } else if (in_vector_kind == Str) {
     sws->get_in_pixels = get_in_pixels_string;
     sws->in.owns_data = 1;
+  } else if (in_vector_kind == PackedBa) {
+    sws->get_in_pixels = get_in_pixels_packed_ba;
   } else {
     sws->get_in_pixels = get_in_pixels_ba;
   }
@@ -446,6 +501,8 @@ CAMLprim value ocaml_swscale_create(value flags_, value in_vector_kind_,
     sws->alloc_out = alloc_out_string;
     sws->copy_out = copy_out_string;
     sws->out.owns_data = 1;
+  } else if (out_vect_kind == PackedBa) {
+    sws->alloc_out = alloc_out_packed_ba;
   } else {
     sws->alloc_out = alloc_out_ba;
   }