PreviewRenderer.cpp revision aef59c544429aae73429a1325d43e830600e3b67 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17
18#define LOG_NDEBUG 1
19#define LOG_TAG "PreviewRenderer"
20#include <utils/Log.h>
21
22#include "PreviewRenderer.h"
23
24#include <media/stagefright/MediaDebug.h>
25#include <surfaceflinger/Surface.h>
26
27namespace android {
28
29PreviewRenderer* PreviewRenderer::CreatePreviewRenderer (
30        const sp<Surface> &surface, size_t width, size_t height) {
31
32    PreviewRenderer* renderer = new PreviewRenderer(surface, width, height);
33
34    if (renderer->init() != 0) {
35        delete renderer;
36        return NULL;
37    }
38
39    return renderer;
40}
41
42PreviewRenderer::PreviewRenderer(
43        const sp<Surface> &surface,
44        size_t width, size_t height)
45    : mSurface(surface),
46      mWidth(width),
47      mHeight(height) {
48}
49
50int PreviewRenderer::init() {
51    int err = 0;
52    ANativeWindow* anw = mSurface.get();
53
54    err = native_window_api_connect(anw, NATIVE_WINDOW_API_CPU);
55    if (err) goto fail;
56
57    err = native_window_set_usage(
58            anw, GRALLOC_USAGE_SW_READ_NEVER | GRALLOC_USAGE_SW_WRITE_OFTEN);
59    if (err) goto fail;
60
61    err = native_window_set_buffer_count(anw, 3);
62    if (err) goto fail;
63
64    err = native_window_set_scaling_mode(
65            anw, NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
66    if (err) goto fail;
67
68    err = native_window_set_buffers_geometry(
69            anw, mWidth, mHeight, HAL_PIXEL_FORMAT_YV12);
70    if (err) goto fail;
71
72    err = native_window_set_buffers_transform(anw, 0);
73    if (err) goto fail;
74
75fail:
76    return err;
77}
78
79PreviewRenderer::~PreviewRenderer() {
80    native_window_api_disconnect(mSurface.get(), NATIVE_WINDOW_API_CPU);
81}
82
83
84//
85// Provides a buffer and associated stride
86// This buffer is allocated by the SurfaceFlinger
87//
88// For optimal display performances, you should :
89// 1) call getBufferYV12()
90// 2) fill the buffer with your data
91// 3) call renderYV12() to take these changes into account
92//
93// For each call to getBufferYV12(), you must also call renderYV12()
94// Expected format in the buffer is YV12 formats (similar to YUV420 planar fromat)
95// for more details on this YV12 cf hardware/libhardware/include/hardware/hardware.h
96//
97void PreviewRenderer::getBufferYV12(uint8_t **data, size_t *stride) {
98    int err = OK;
99
100    if ((err = mSurface->ANativeWindow::dequeueBuffer(mSurface.get(), &mBuf)) != 0) {
101        LOGW("Surface::dequeueBuffer returned error %d", err);
102        return;
103    }
104
105    CHECK_EQ(0, mSurface->ANativeWindow::lockBuffer(mSurface.get(), mBuf));
106
107    GraphicBufferMapper &mapper = GraphicBufferMapper::get();
108
109    Rect bounds(mWidth, mHeight);
110
111    void *dst;
112    CHECK_EQ(0, mapper.lock(mBuf->handle,
113            GRALLOC_USAGE_SW_READ_NEVER | GRALLOC_USAGE_SW_WRITE_OFTEN,
114            bounds, &dst));
115
116    *data   = (uint8_t*)dst;
117    *stride = mBuf->stride;
118}
119
120
121//
122// Display the content of the buffer provided by last call to getBufferYV12()
123//
124// See getBufferYV12() for details.
125//
126void PreviewRenderer::renderYV12() {
127    int err = OK;
128
129    GraphicBufferMapper &mapper = GraphicBufferMapper::get();
130
131    if (mBuf!= NULL) {
132        CHECK_EQ(0, mapper.unlock(mBuf->handle));
133
134        if ((err = mSurface->ANativeWindow::queueBuffer(mSurface.get(), mBuf)) != 0) {
135            LOGW("Surface::queueBuffer returned error %d", err);
136        }
137    }
138    mBuf = NULL;
139}
140
141}  // namespace android
142