PreviewRenderer.cpp revision 08b82bddf54757ad6bd243181f1b68a79bb70e6d 
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
53    err = native_window_api_connect(mSurface.get(), NATIVE_WINDOW_API_CPU);
54    if (err) goto fail;
55
56    err = native_window_set_usage(mSurface.get(),
57            GRALLOC_USAGE_SW_READ_NEVER | GRALLOC_USAGE_SW_WRITE_OFTEN);
58    if (err) goto fail;
59
60    err = native_window_set_buffer_count(mSurface.get(), 3);
61    if (err) goto fail;
62
63    err = native_window_set_scaling_mode(
64            mSurface.get(), NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
65    if (err) goto fail;
66
67    err = native_window_set_buffers_geometry(
68            mSurface.get(),
69            mWidth, mHeight,
70            HAL_PIXEL_FORMAT_YV12);
71    if (err) goto fail;
72
73fail:
74    return err;
75}
76
77PreviewRenderer::~PreviewRenderer() {
78    native_window_api_disconnect(mSurface.get(), NATIVE_WINDOW_API_CPU);
79}
80
81
82//
83// Provides a buffer and associated stride
84// This buffer is allocated by the SurfaceFlinger
85//
86// For optimal display performances, you should :
87// 1) call getBufferYV12()
88// 2) fill the buffer with your data
89// 3) call renderYV12() to take these changes into account
90//
91// For each call to getBufferYV12(), you must also call renderYV12()
92// Expected format in the buffer is YV12 formats (similar to YUV420 planar fromat)
93// for more details on this YV12 cf hardware/libhardware/include/hardware/hardware.h
94//
95void PreviewRenderer::getBufferYV12(uint8_t **data, size_t *stride) {
96    int err = OK;
97
98    if ((err = mSurface->ANativeWindow::dequeueBuffer(mSurface.get(), &mBuf)) != 0) {
99        LOGW("Surface::dequeueBuffer returned error %d", err);
100        return;
101    }
102
103    CHECK_EQ(0, mSurface->ANativeWindow::lockBuffer(mSurface.get(), mBuf));
104
105    GraphicBufferMapper &mapper = GraphicBufferMapper::get();
106
107    Rect bounds(mWidth, mHeight);
108
109    void *dst;
110    CHECK_EQ(0, mapper.lock(mBuf->handle,
111            GRALLOC_USAGE_SW_READ_NEVER | GRALLOC_USAGE_SW_WRITE_OFTEN,
112            bounds, &dst));
113
114    *data   = (uint8_t*)dst;
115    *stride = mBuf->stride;
116}
117
118
119//
120// Display the content of the buffer provided by last call to getBufferYV12()
121//
122// See getBufferYV12() for details.
123//
124void PreviewRenderer::renderYV12() {
125    int err = OK;
126
127    GraphicBufferMapper &mapper = GraphicBufferMapper::get();
128
129    if (mBuf!= NULL) {
130        CHECK_EQ(0, mapper.unlock(mBuf->handle));
131
132        if ((err = mSurface->ANativeWindow::queueBuffer(mSurface.get(), mBuf)) != 0) {
133            LOGW("Surface::queueBuffer returned error %d", err);
134        }
135    }
136    mBuf = NULL;
137}
138
139}  // namespace android
140