关键代码梳理

视频解封装,将音视频流逐帧分成Packet放到相应的队列

// 解码操作void NativePlayer::codec_internal() {    int ret = 0;    while (isPlaying) {        // 判断队列是否已满        if (audioChannel && audioChannel->packetQueue.size() > QUEUE_MAX_SIZE) {            // 音频的包已经满了,线程睡10ms            av_usleep(THREAD_SLEEP_TIME);            continue;        }        if (videoChannel && videoChannel->packetQueue.size() > QUEUE_MAX_SIZE) {            // 视频的包已经满了,线程睡10ms            av_usleep(THREAD_SLEEP_TIME);            continue;        }        // 读取数据包        AVPacket *avPacket = av_packet_alloc();        ret = av_read_frame(avFormatContext, avPacket);        if (ret == 0) {            // 将数据包放到队列中            if (audioChannel && avPacket->stream_index == audioChannel->channelId) {                audioChannel->packetQueue.push(avPacket);            } else if (videoChannel && avPacket->stream_index == videoChannel->channelId) {                videoChannel->packetQueue.push(avPacket);            }        } else if (ret == AVERROR_EOF) {            // 读取完毕, 但不一定是播放完毕,只是将数据包全部放到队列中了            if (videoChannel->packetQueue.empty() && videoChannel->frameQueue.empty()                && audioChannel->packetQueue.empty() && audioChannel->frameQueue.empty()) {                LOGE("播放完毕...");                break;            }            // 因为seek的存在,就算读取完毕,依然要循环下去, 执行av_read_frame(否则seek无效)        } else {            break;        }    }    isPlaying = false;    if (audioChannel) {        audioChannel->stop();    }    if (videoChannel) {        videoChannel->stop();    }}

视频Packet->视频Frame

// 将packet转成frame, 是packetQueue的消费者, 是frameQueue的生产者void VideoChannel::decode_packet_internal() {    // 子线程运行    AVPacket *avPacket = 0;    while (isPlaying) {        int ret = packetQueue.pop(avPacket);        if (!isPlaying) {            break;        }        if (!ret) {            continue;        }        ret = avcodec_send_packet(codecContext, avPacket);        if (ret == AVERROR(EAGAIN)) {            // 需要更多的数据            continue;        } else if (ret < 0) {            // 失败            break;        }        releaseAvPacket(avPacket);        AVFrame *avFrame = av_frame_alloc();        ret = avcodec_receive_frame(codecContext, avFrame);        if (ret == AVERROR(EAGAIN)) {            // 需要更多的数据            continue;        } else if (ret < 0) {            // 失败            break;        }        frameQueue.push(avFrame);        while (frameQueue.size() > QUEUE_MAX_SIZE && isPlaying) {            av_usleep(THREAD_SLEEP_TIME);        }    }    releaseAvPacket(avPacket);}

解码视频,Frame转成RGBA数组

// 在子线程循环, 从frameQueue中取数据,是frameQueue的消费者void VideoChannel::play_internal() {    // 初始化转换上下文, 将I420 的帧转成 rgba的帧    SwsContext *sws_cxt = sws_getContext(            codecContext->width, codecContext->height, codecContext->pix_fmt,            codecContext->width, codecContext->height, AV_PIX_FMT_RGBA,            SWS_BILINEAR, 0, 0, 0);    // 4个通道,分别是RGBA    // !!!! 这个数组不能声明成[1]  否则报错都看不懂!!!!    uint8_t *dst_data[4];    int dst_linesize[4];    // 创建一个画布    av_image_alloc(dst_data, dst_linesize,                   codecContext->width, codecContext->height, AV_PIX_FMT_RGBA, 1);    AVFrame *avFrame = 0;    while (isPlaying) {        int ret = frameQueue.pop(avFrame);        if (!isPlaying) {            break;        }        if (!ret) {            continue;        }        while (isPause) {            av_usleep(THREAD_SLEEP_TIME);        }        // 执行转换        sws_scale(sws_cxt,                  avFrame->data, avFrame->linesize, 0, avFrame->height,                  dst_data, dst_linesize);        // 回调到native-lib中绘制到ANativeWindow中        renderFrame(dst_data[0], dst_linesize[0], codecContext->width, codecContext->height);        // 音视频同步处理        // pts 是编码的时候赋值的, 需要加上解码的时间        clock = avFrame->pts * av_q2d(time_base);        // 解码时间, 因为配置差的手机 解码耗时多        double extra_delay = avFrame->repeat_pict / (2 * fps);        double frame_delay = 1.0 / fps;        double audio_clock = audioChannel->clock;        double diff = clock - audio_clock;        double delay = extra_delay + frame_delay;//        LOGE("----相差----%f", diff);        if (clock > audio_clock) {            // 视频超前            if (diff > 1) {                // 差太久 慢慢赶                av_usleep((delay * 2) * 1000 * 1000);            } else {                av_usleep((delay + diff) * 1000 * 1000);            }        } else {            // 音频超前            if (diff > 1) {                // 超太多,放弃同步            } else if (diff >= 0.05) {                // 视频需要追赶,丢帧                // 删除frame队列的非关键帧                // 减少睡眠时间的话会震荡                frameQueue.sync();            } else {                // 视为同步了            }        }//        av_usleep(16 * 1000);        releaseAvFrame(avFrame);    }    if (dst_data[0]) {        av_freep(&dst_data[0]);    }    isPlaying = false;    releaseAvFrame(avFrame);    sws_freeContext(sws_cxt);}

将RGBA数据渲染到ANativeWindow

void renderFrame(uint8_t *data, int linesize, int width, int height) {    pthread_mutex_lock(&mutex);    // 将rgb的数据渲染到窗口    // 设置窗口属性    if (!window) {        pthread_mutex_unlock(&mutex);        ANativeWindow_release(window);        return;    }    ANativeWindow_setBuffersGeometry(window, width, height, WINDOW_FORMAT_RGBA_8888);    // 锁缓冲区    if (ANativeWindow_lock(window, &buffer, 0)) {        ANativeWindow_release(window);        window = 0;        pthread_mutex_unlock(&mutex);        return;    }    // 输出到屏幕的输入源    uint8_t *srcFirstLine = data;    // 输出到屏幕的输入源的行数    int srcStride = linesize;    // 输出到屏幕时的跨度 是 缓冲区的跨度 * 4 , 因为一个pixel是4个字节    int windowStride = buffer.stride * 4;    // 屏幕的首行地址    uint8_t *windowFirstLine = (uint8_t *) buffer.bits;    for (int i = 0; i < buffer.height; ++i) {        memcpy(windowFirstLine + i * windowStride, srcFirstLine + i * srcStride,               windowStride);    }    // 解锁缓冲区    ANativeWindow_unlockAndPost(window);    pthread_mutex_unlock(&mutex);}

音频OpenSL ES初始化

// 在子线程初始化OpenSLESvoid AudioChannel::initOpenSLES_internal() {    // 流程    /**     * 创建音频引擎     * 设置混响器     * 创建播放器     * 设置缓存队列和回调函数     * 设置播放状态     * 启动回调函数     */    // 音频引擎    SLEngineItf engineInterface = NULL;    // 音频对象    SLObjectItf engineObject = NULL;    // 混响器对象    SLObjectItf outputMixObject = NULL;    // 播放器对象    SLObjectItf bqPlayerObject = NULL;    // 回调接口    SLPlayItf bqPlayerInterface = NULL;    // 缓冲队列    SLAndroidSimpleBufferQueueItf bqPlayerBufferQueue = NULL;    // 初始化播放引擎    SLresult result;    result = slCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);    if (SL_RESULT_SUCCESS != result) {        return;    }    result = (*engineObject)->Realize(engineObject, SL_BOOLEAN_FALSE);    if (SL_RESULT_SUCCESS != result) {        return;    }    // 初始化音频接口    result = (*engineObject)->GetInterface(engineObject, SL_IID_ENGINE, &engineInterface);    if (SL_RESULT_SUCCESS != result) {        return;    }    //初始化播放引擎    // 创建混响器    result = (*engineInterface)->CreateOutputMix(engineInterface, &outputMixObject, 0, 0, 0);    if (SL_RESULT_SUCCESS != result) {        return;    }    // 初始化混响器/    result = (*outputMixObject)->Realize(outputMixObject, SL_BOOLEAN_FALSE);    if (SL_RESULT_SUCCESS != result) {        return;    }    // 设置数据源的信息    SLDataLocator_AndroidSimpleBufferQueue slDataLocatorAndroidSimpleBufferQueue            = {SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE, 2};    SLDataFormat_PCM pcm = {            SL_DATAFORMAT_PCM, // 播放pcm格式的数据            2, // 2个声道,立体声            SL_SAMPLINGRATE_44_1, // 44100hz的频率            SL_PCMSAMPLEFORMAT_FIXED_16, // 采样位数16位            SL_PCMSAMPLEFORMAT_FIXED_16,            SL_SPEAKER_FRONT_LEFT | SL_SPEAKER_FRONT_RIGHT, // 立体声(前左前右)            SL_BYTEORDER_LITTLEENDIAN // 小端模式    };    SLDataSource slDataSource = {&slDataLocatorAndroidSimpleBufferQueue, &pcm};    SLDataLocator_OutputMix loc_outmix = {SL_DATALOCATOR_OUTPUTMIX, outputMixObject};    SLDataSink audioSnk = {&loc_outmix, NULL};    const SLInterfaceID ids[1] = {SL_IID_BUFFERQUEUE};    const SLboolean req[1] = {SL_BOOLEAN_TRUE};    // 创建播放器    (*engineInterface)->CreateAudioPlayer(            engineInterface,// 播放器接口            &bqPlayerObject,// 播放器            &slDataSource,// 播放器参数 播放缓冲队列 播放格式            &audioSnk,// 播放缓冲区            1,// 接口回调个数            ids,// 设置播放队列id            req// 是否采用内置的缓冲区    );    // 初始化播放器    (*bqPlayerObject)->Realize(bqPlayerObject, SL_BOOLEAN_FALSE);    // 得到接口后调用 获取Player接口    (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_PLAY, &bqPlayerInterface);    // 获得播放器接口    (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_BUFFERQUEUE, &bqPlayerBufferQueue);    // 注册回调    (*bqPlayerBufferQueue)->RegisterCallback(bqPlayerBufferQueue, bqPlayerCallback, this);    // 设置播放状态--    (*bqPlayerInterface)->SetPlayState(bqPlayerInterface, SL_PLAYSTATE_PLAYING);    // 启动回调函数    bqPlayerCallback(bqPlayerBufferQueue, this);}

音频Packet->Frame

// 在子线程编码,将Packet编码成framevoid AudioChannel::codec_internal() {    // 子线程运行    AVPacket *avPacket = 0;    while (isPlaying) {        int ret = packetQueue.pop(avPacket);        if (!isPlaying) {            break;        }        if (!ret) {            continue;        }        ret = avcodec_send_packet(codecContext, avPacket);        if (ret == AVERROR(EAGAIN)) {            // 需要更多的数据            continue;        } else if (ret < 0) {            // 失败            break;        }        releaseAvPacket(avPacket);        AVFrame *avFrame = av_frame_alloc();        ret = avcodec_receive_frame(codecContext, avFrame);        if (ret == AVERROR(EAGAIN)) {            // 需要更多的数据            continue;        } else if (ret < 0) {            // 失败            break;        }        frameQueue.push(avFrame);        while (frameQueue.size() > QUEUE_MAX_SIZE && isPlaying) {            av_usleep(THREAD_SLEEP_TIME);        }    }    releaseAvPacket(avPacket);}

音频frame数据转pcm源数据

// 将frame的数据放到buffer中int AudioChannel::getBufferSize() {    AVFrame *avFrame = 0;    int out_buffer_size = 0;    while (isPlaying) {        int ret = frameQueue.pop(avFrame);        if (!isPlaying) {            break;        }        if (!ret) {            continue;        }        while (isPause) {            av_usleep(THREAD_SLEEP_TIME);        }        int64_t dst_nb_samples = av_rescale_rnd(                swr_get_delay(swrContext, avFrame->sample_rate) + avFrame->nb_samples,                out_sample_rate,                avFrame->sample_rate,                AV_ROUND_UP);        // frame --> 统一格式        int nb = swr_convert(swrContext, &out_buffer, dst_nb_samples,                             (const uint8_t **) avFrame->data,                             avFrame->nb_samples);        // 获取当前帧的实际大小        out_buffer_size = nb * out_channel_nb * out_samplesize;        //av_samples_get_buffer_size(NULL, out_channel_nb, avFrame->nb_samples,out_sample,1);        clock = avFrame->pts * av_q2d(time_base);        break;    }    if (javaCallHelper) {        javaCallHelper->onProgress(THREAD_CHILD, clock);    }    releaseAvFrame(avFrame);    return out_buffer_size;}

OpenSL ES 渲染音频

// 注册给bqPlayerBufferQueue的回调函数void bqPlayerCallback(SLAndroidSimpleBufferQueueItf bq, void *context) {    AudioChannel *audioChannel = static_cast(context);    int lenth = audioChannel->getBufferSize();    if (lenth > 0) {        (*bq)->Enqueue(bq, audioChannel->out_buffer, lenth);    }}

基于FFmpeg的音视频播放器

关键代码梳理

视频解封装,将音视频流逐帧分成Packet放到相应的队列

视频Packet->视频Frame

解码视频,Frame转成RGBA数组

将RGBA数据渲染到ANativeWindow

音频OpenSL ES初始化

音频Packet->Frame

音频frame数据转pcm源数据

OpenSL ES 渲染音频

更多相关文章

随机推荐