ppapi/api/ppb_video_decoder.idl

   1 /* Copyright (c) 2014 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file.
   4  */
   5
   6 /**
   7  * This file defines the <code>PPB_VideoDecoder</code> interface.
   8  */
   9
  10 [generate_thunk]
  11
  12 label Chrome {
  13   [channel=dev] M36 = 0.1
  14 };
  15
  16 /**
  17  * Video decoder interface.
  18  *
  19  * Typical usage:
  20  * - Call Create() to create a new video decoder resource.
  21  * - Call Initialize() to initialize it with a 3d graphics context and the
  22  *   desired codec profile.
  23  * - Call Decode() continuously (waiting for each previous call to complete) to
  24  *   push bitstream buffers to the decoder.
  25  * - Call GetPicture() continuously (waiting for each previous call to complete)
  26  *   to pull decoded pictures from the decoder.
  27  * - Call Flush() to signal end of stream to the decoder and perform shutdown
  28  *   when it completes.
  29  * - Call Reset() to quickly stop the decoder (e.g. to implement Seek) and wait
  30  *   for the callback before restarting decoding at another point.
  31  * - To destroy the decoder, the plugin should release all of its references to
  32  *   it. Any pending callbacks will abort before the decoder is destroyed.
  33  *
  34  * Available video codecs vary by platform.
  35  * All: theora, vorbis, vp8.
  36  * Chrome and ChromeOS: aac, h264.
  37  * ChromeOS: mpeg4.
  38  */
  39 interface PPB_VideoDecoder {
  40   /**
  41    * Creates a new video decoder resource.
  42    *
  43    * @param[in] instance A <code>PP_Instance</code> identifying the instance
  44    * with the video decoder.
  45    *
  46    * @return A <code>PP_Resource</code> corresponding to a video decoder if
  47    * successful or 0 otherwise.
  48    */
  49   PP_Resource Create(
  50       [in] PP_Instance instance);
  51
  52   /**
  53    * Determines if the given resource is a video decoder.
  54    *
  55    * @param[in] resource A <code>PP_Resource</code> identifying a resource.
  56    *
  57    * @return <code>PP_TRUE</code> if the resource is a
  58    * <code>PPB_VideoDecoder</code>, <code>PP_FALSE</code> if the resource is
  59    * invalid or some other type.
  60    */
  61   PP_Bool IsVideoDecoder(
  62       [in] PP_Resource resource);
  63
  64   /**
  65    * Initializes a video decoder resource. This should be called after Create()
  66    * and before any other functions.
  67    *
  68    * @param[in] video_decoder A <code>PP_Resource</code> identifying the video
  69    * decoder.
  70    * @param[in] graphics3d_context A <code>PPB_Graphics3D</code> resource to use
  71    * during decoding.
  72    * @param[in] profile A <code>PP_VideoProfile</code> specifying the video
  73    * codec profile.
  74    * @param[in] allow_software_fallback A <code>PP_Bool</code> specifying
  75    * whether the decoder can fall back to software decoding if a suitable
  76    * hardware decoder isn't available.
  77    * @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
  78    * completion.
  79    *
  80    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
  81    * Returns PP_ERROR_NOTSUPPORTED if video decoding is not available, or the
  82    * requested profile is not supported. In this case, the client may call
  83    * Initialize() again with different parameters to find a good configuration.
  84    */
  85   int32_t Initialize(
  86       [in] PP_Resource video_decoder,
  87       [in] PP_Resource graphics3d_context,
  88       [in] PP_VideoProfile profile,
  89       [in] PP_Bool allow_software_fallback,
  90       [in] PP_CompletionCallback callback);
  91
  92   /**
  93    * Decodes a bitstream buffer. Copies |size| bytes of data from the plugin's
  94    * |buffer|. The plugin should wait until the decoder signals completion by
  95    * returning PP_OK or by running |callback| before calling Decode() again.
  96    *
  97    * In general, each bitstream buffer should contain a demuxed bitstream frame
  98    * for the selected video codec. For example, H264 decoders expect to receive
  99    * one AnnexB NAL unit, including the 4 byte start code prefix, while VP8
 100    * decoders expect to receive a bitstream frame without the IVF frame header.
 101    *
 102    * If the call to Decode() eventually results in a picture, the |decode_id|
 103    * parameter is copied into the returned picture. The plugin can use this to
 104    * associate decoded pictures with Decode() calls (e.g. to assign timestamps
 105    * or frame numbers to pictures.) This value is opaque to the API so the
 106    * plugin is free to pass any value.
 107    *
 108    * @param[in] video_decoder A <code>PP_Resource</code> identifying the video
 109    * decoder.
 110    * @param[in] decode_id An optional value, chosen by the plugin, that can be
 111    * used to associate calls to Decode() with decoded pictures returned by
 112    * GetPicture().
 113    * @param[in] size Buffer size in bytes.
 114    * @param[in] buffer Starting address of buffer.
 115    * @param[in] callback A <code>PP_CompletionCallback</code> to be called on
 116    * completion.
 117    *
 118    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
 119    * Returns PP_ERROR_FAILED if the decoder isn't initialized or if a Flush()
 120    * or Reset() call is pending.
 121    * Returns PP_ERROR_INPROGRESS if there is another Decode() call pending.
 122    * Returns PP_ERROR_NOMEMORY if a bitstream buffer can't be created.
 123    * Returns PP_ERROR_ABORTED when Reset() is called while Decode() is pending.
 124    */
 125   int32_t Decode(
 126       [in] PP_Resource video_decoder,
 127       [in] uint32_t decode_id,
 128       [in] uint32_t size,
 129       [in] mem_t buffer,
 130       [in] PP_CompletionCallback callback);
 131
 132   /**
 133    * Gets the next picture from the decoder. The picture is valid after the
 134    * decoder signals completion by returning PP_OK or running |callback|. The
 135    * plugin can call GetPicture() again after the decoder signals completion.
 136    * When the plugin is finished using the picture, it should return it to the
 137    * system by calling RecyclePicture().
 138    *
 139    * @param[in] video_decoder A <code>PP_Resource</code> identifying the video
 140    * decoder.
 141    * @param[out] picture A <code>PP_VideoPicture</code> to hold the decoded
 142    * picture.
 143    * @param[in] callback A <code>PP_CompletionCallback</code> to be called on
 144    * completion.
 145    *
 146    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
 147    * Returns PP_ERROR_FAILED if the decoder isn't initialized or if a Reset()
 148    * call is pending.
 149    * Returns PP_ERROR_INPROGRESS if there is another GetPicture() call pending.
 150    * Returns PP_ERROR_ABORTED when Reset() is called, or if a call to Flush()
 151    * completes while GetPicture() is pending.
 152    */
 153   int32_t GetPicture(
 154       [in] PP_Resource video_decoder,
 155       [out] PP_VideoPicture picture,
 156       [in] PP_CompletionCallback callback);
 157
 158   /**
 159    * Recycles a picture that the plugin has received from the decoder.
 160    * The plugin should call this as soon as it has finished using the texture so
 161    * the decoder can decode more pictures.
 162    *
 163    * @param[in] video_decoder A <code>PP_Resource</code> identifying the video
 164    * decoder.
 165    * @param[in] picture A <code>PP_VideoPicture</code> to return to
 166    * the decoder.
 167    */
 168   void RecyclePicture(
 169       [in] PP_Resource video_decoder,
 170       [in] PP_VideoPicture picture);
 171
 172   /**
 173    * Flushes the decoder. The plugin should call Flush() when it reaches the
 174    * end of its video stream in order to stop cleanly. The decoder will run any
 175    * pending Decode() call to completion. The plugin should make no further
 176    * calls to the decoder other than GetPicture() and RecyclePicture() until
 177    * the decoder signals completion by running |callback|. Just before
 178    * completion, any pending GetPicture() call will complete by running its
 179    * callback with result PP_ERROR_ABORTED to signal that no more pictures are
 180    * available. The plugin should recycle any pictures it is using before
 181    * resuming decoding.
 182    *
 183    * @param[in] video_decoder A <code>PP_Resource</code> identifying the video
 184    * decoder.
 185    * @param[in] callback A <code>PP_CompletionCallback</code> to be called on
 186    * completion.
 187    *
 188    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
 189    * Returns PP_ERROR_FAILED if the decoder isn't initialized.
 190    */
 191   int32_t Flush(
 192       [in] PP_Resource video_decoder,
 193       [in] PP_CompletionCallback callback);
 194
 195   /**
 196    * Resets the decoder as quickly as possible. The plugin can call Reset() to
 197    * skip to another position in the video stream. After Reset() returns, any
 198    * pending calls to Decode() and GetPicture()) abort, causing their callbacks
 199    * to run with PP_ERROR_ABORTED. The plugin should not make further calls to
 200    * the decoder until the decoder signals completion by running |callback|.
 201    * The pictures in use by the plugin remain valid until decoding is resumed,
 202    * but need not be recycled.
 203    *
 204    * @param[in] video_decoder A <code>PP_Resource</code> identifying the video
 205    * decoder.
 206    * @param[in] callback A <code>PP_CompletionCallback</code> to be called on
 207    * completion.
 208    *
 209    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
 210    * Returns PP_ERROR_FAILED if the decoder isn't initialized.
 211    */
 212   int32_t Reset(
 213       [in] PP_Resource video_decoder,
 214       [in] PP_CompletionCallback callback);
 215 };