theora 0.4.1 · OCaml Package

* Functions for encoding theora files using libtheora. * *

author Samuel Mimram

author Romain Beauxis

Exceptions

exception Internal_error

General failure.

exception Invalid_data

Library encountered invalid internal data.

exception Unknown_error of int

An unhandled error happened.

exception Duplicate_frame

The decoded packet represented a dropped frame. * The player can continue to display the current frame, * as the contents of the decoded frame buffer have not * changed.

exception Done

Exceptions used by the decoding module.

exception Not_initialized

exception Bad_packet

exception Header_not_theora

exception Bad_header

exception Not_implemented

General functions

val version_string : string

* Human-readable string to identify the encoder vendor and version.

val version_number : int * int * int

major, minor and sub version numbers of the encoder.

val is_keyframe : Ogg.Stream.packet -> bool

Determines whether a theora packet is a key frame or not. * * raises Invalid_data if The packet is not a video data * packet.

Types and datastructures

type colorspace =

| CS_unspecified
(*
The colorspace is unknown or unspecified
*)
| CS_ITU_REC_470M
(*
This is the best option for 'NTSC' content
*)
| CS_ITU_REC_470BG
(*
This is the best option for 'PAL' content
*)
| CS_NSPACES
(*
This marks the end of the defined colorspaces
*)

A Colorspace.

type pixelformat =

| PF_420
(*
Chroma subsampling by 2 in each direction (4:2:0)
*)
| PF_reserved
(*
Reserved value
*)
| PF_422
(*
Horizonatal chroma subsampling by 2 (4:2:2)
*)
| PF_444
(*
No chroma subsampling at all (4:4:4)
*)

* A Chroma subsampling * * These enumerate the available chroma subsampling options supported * by the theora format. See Section 4.4 of the specification for * exact definitions.

type info = {

frame_width : int;
(*
The encoded frame width.
*)
frame_height : int;
(*
The encoded frame height.
*)
picture_width : int;
(*
The displayed picture width.
*)
picture_height : int;
(*
The displayed picture height.
*)
picture_x : int;
(*
The X offset of the displayed picture.
*)
picture_y : int;
(*
The Y offset of the displayed picture.
*)
colorspace : colorspace;
(*
The color space.
*)
pixel_fmt : pixelformat;
(*
The pixel format.
*)
target_bitrate : int;
(*
The target bit-rate in bits per second.
*)
quality : int;
(*
The target quality level.
*)
keyframe_granule_shift : int;
(*
The amount to shift to extract the last keyframe number from the granule position.
*)
version_major : int;
version_minor : int;
version_subminor : int;
fps_numerator : int;
fps_denominator : int;
aspect_numerator : int;
aspect_denominator : int;

}

Theora bitstream info.

val default_granule_shift : int

type data_buffer =
  (int, Stdlib.Bigarray.int8_unsigned_elt, Stdlib.Bigarray.c_layout)
    Stdlib.Bigarray.Array1.t

type yuv_buffer = {

y_width : int;
y_height : int;
y_stride : int;
y : data_buffer;
u_width : int;
u_height : int;
u_stride : int;
u : data_buffer;
v_width : int;
v_height : int;
v_stride : int;
v : data_buffer;

}

* A YUV buffer for passing uncompressed frames to and from the codec. * This holds a Y'CbCr frame in planar format. The CbCr planes can be * subsampled and have their own separate dimensions and row stride * offsets. Note that the strides may be negative in some * configurations. For theora the width and height of the largest plane * must be a multiple of 16. The actual meaningful picture size and * offset are stored in the info structure; frames returned by * the decoder may need to be cropped for display. * * All samples are 8 bits. Within each plane samples are ordered by * row from the top of the frame to the bottom. Within each row samples * are ordered from left to right.

Encoding

module Encoder : sig ... end

module Decoder : sig ... end

module Skeleton : sig ... end

package theora

Exceptions

General functions

Types and datastructures

Encoding