1/* 2 * Copyright (C) 2015 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//#define LOG_NDEBUG 0 18#define LOG_TAG "FrameDropper" 19#include <utils/Log.h> 20 21#include <media/stagefright/bqhelper/FrameDropper.h> 22#include <media/stagefright/foundation/ADebug.h> 23 24namespace android { 25 26static const int64_t kMaxJitterUs = 2000; 27 28FrameDropper::FrameDropper() 29 : mDesiredMinTimeUs(-1), 30 mMinIntervalUs(0) { 31} 32 33FrameDropper::~FrameDropper() { 34} 35 36status_t FrameDropper::setMaxFrameRate(float maxFrameRate) { 37 if (maxFrameRate < 0) { 38 mMinIntervalUs = -1ll; 39 return OK; 40 } 41 42 if (maxFrameRate == 0) { 43 ALOGE("framerate should be positive but got %f.", maxFrameRate); 44 return BAD_VALUE; 45 } 46 mMinIntervalUs = (int64_t) (1000000.0f / maxFrameRate); 47 return OK; 48} 49 50bool FrameDropper::shouldDrop(int64_t timeUs) { 51 if (mMinIntervalUs <= 0) { 52 return false; 53 } 54 55 if (mDesiredMinTimeUs < 0) { 56 mDesiredMinTimeUs = timeUs + mMinIntervalUs; 57 ALOGV("first frame %lld, next desired frame %lld", 58 (long long)timeUs, (long long)mDesiredMinTimeUs); 59 return false; 60 } 61 62 if (timeUs < (mDesiredMinTimeUs - kMaxJitterUs)) { 63 ALOGV("drop frame %lld, desired frame %lld, diff %lld", 64 (long long)timeUs, (long long)mDesiredMinTimeUs, 65 (long long)(mDesiredMinTimeUs - timeUs)); 66 return true; 67 } 68 69 int64_t n = (timeUs - mDesiredMinTimeUs + kMaxJitterUs) / mMinIntervalUs; 70 mDesiredMinTimeUs += (n + 1) * mMinIntervalUs; 71 ALOGV("keep frame %lld, next desired frame %lld, diff %lld", 72 (long long)timeUs, (long long)mDesiredMinTimeUs, 73 (long long)(mDesiredMinTimeUs - timeUs)); 74 return false; 75} 76 77} // namespace android 78