vpx/vp9/vp9_iface_common.h
John Koleszar 679e4abdd5 Initial version of alpha channel support
This is a mostly-working implementation of an extra channel in the
bitstream. Configure with --enable-alpha to test. Notable TODOs:

 - Add extra channel to all mismatch tests, PSNR, SSIM, etc
 - Configurable subsampling
 - Variable number of planes (currently always uses all 4)
 - Loop filtering
 - Per-plane lossless quantizer
 - ARNR support

This implementation just uses the same contents as the Y channel
for the A channel, due to lack of content and general pain in
playing back 4 channel content. A later patch will use the actual
alpha channel passed in from outside the codec.

Change-Id: Ibf81f023b1c570bd84b3064e9b4b8ae52e087592
2013-05-16 22:21:09 -07:00

90 lines
3.2 KiB
C

/*
* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef VP9_VP9_IFACE_COMMON_H_
#define VP9_VP9_IFACE_COMMON_H_
static void yuvconfig2image(vpx_image_t *img, const YV12_BUFFER_CONFIG *yv12,
void *user_priv) {
/** vpx_img_wrap() doesn't allow specifying independent strides for
* the Y, U, and V planes, nor other alignment adjustments that
* might be representable by a YV12_BUFFER_CONFIG, so we just
* initialize all the fields.*/
int bps = 12;
if (yv12->uv_height == yv12->y_height) {
if (yv12->uv_width == yv12->y_width) {
img->fmt = VPX_IMG_FMT_I444;
bps = 24;
} else {
img->fmt = VPX_IMG_FMT_I422;
bps = 16;
}
} else {
img->fmt = VPX_IMG_FMT_I420;
}
img->w = yv12->y_stride;
img->h = multiple16(yv12->y_height + 2 * VP9BORDERINPIXELS);
img->d_w = yv12->y_crop_width;
img->d_h = yv12->y_crop_height;
img->x_chroma_shift = yv12->uv_width < yv12->y_width;
img->y_chroma_shift = yv12->uv_height < yv12->y_height;
img->planes[VPX_PLANE_Y] = yv12->y_buffer;
img->planes[VPX_PLANE_U] = yv12->u_buffer;
img->planes[VPX_PLANE_V] = yv12->v_buffer;
img->planes[VPX_PLANE_ALPHA] = yv12->alpha_buffer;
img->stride[VPX_PLANE_Y] = yv12->y_stride;
img->stride[VPX_PLANE_U] = yv12->uv_stride;
img->stride[VPX_PLANE_V] = yv12->uv_stride;
img->stride[VPX_PLANE_ALPHA] = yv12->alpha_stride;
img->bps = bps;
img->user_priv = user_priv;
img->img_data = yv12->buffer_alloc;
img->img_data_owner = 0;
img->self_allocd = 0;
}
static vpx_codec_err_t image2yuvconfig(const vpx_image_t *img,
YV12_BUFFER_CONFIG *yv12) {
yv12->y_buffer = img->planes[VPX_PLANE_Y];
yv12->u_buffer = img->planes[VPX_PLANE_U];
yv12->v_buffer = img->planes[VPX_PLANE_V];
yv12->alpha_buffer = img->planes[VPX_PLANE_ALPHA];
yv12->y_crop_width = img->d_w;
yv12->y_crop_height = img->d_h;
yv12->y_width = img->d_w;
yv12->y_height = img->d_h;
yv12->uv_width = img->x_chroma_shift == 1 ? (1 + yv12->y_width) / 2
: yv12->y_width;
yv12->uv_height = img->y_chroma_shift == 1 ? (1 + yv12->y_height) / 2
: yv12->y_height;
yv12->alpha_width = yv12->alpha_buffer ? img->d_w : 0;
yv12->alpha_height = yv12->alpha_buffer ? img->d_h : 0;
yv12->y_stride = img->stride[VPX_PLANE_Y];
yv12->uv_stride = img->stride[VPX_PLANE_U];
yv12->alpha_stride = yv12->alpha_buffer ? img->stride[VPX_PLANE_ALPHA] : 0;
yv12->border = (img->stride[VPX_PLANE_Y] - img->w) / 2;
yv12->clrtype = REG_YUV;
#if CONFIG_ALPHA
// For development purposes, force alpha to hold the same data a Y for now.
yv12->alpha_buffer = yv12->y_buffer;
yv12->alpha_width = yv12->y_width;
yv12->alpha_height = yv12->y_height;
yv12->alpha_stride = yv12->y_stride;
#endif
return VPX_CODEC_OK;
}
#endif // VP9_VP9_IFACE_COMMON_H_