From 3e4def578d5521174f133c9922fb541066f141af Mon Sep 17 00:00:00 2001 From: xufulong <839789740@qq.com> Date: Tue, 14 Apr 2020 23:36:58 +0800 Subject: [PATCH] translate note into English translate note into English --- app/src/main/cpp/ffprobe_cmd.c | 18 ++--- app/src/main/cpp/media_player.c | 128 ++++++++++++++------------------ 2 files changed, 65 insertions(+), 81 deletions(-) diff --git a/app/src/main/cpp/ffprobe_cmd.c b/app/src/main/cpp/ffprobe_cmd.c index b702339..0f3106d 100644 --- a/app/src/main/cpp/ffprobe_cmd.c +++ b/app/src/main/cpp/ffprobe_cmd.c @@ -8,22 +8,22 @@ #include #include -FFMPEG_FUNC(jstring , handleProbe, jobjectArray commands) { +FFMPEG_FUNC(jstring, handleProbe, jobjectArray commands) { int argc = (*env)->GetArrayLength(env, commands); - char **argv = (char**)malloc(argc * sizeof(char*)); + char **argv = (char **) malloc(argc * sizeof(char *)); int i; for (i = 0; i < argc; i++) { - jstring jstr = (jstring) (*env)->GetObjectArrayElement(env, commands, i); - char* temp = (char*) (*env)->GetStringUTFChars(env, jstr, 0); - argv[i] = malloc(1024); - strcpy(argv[i], temp); - (*env)->ReleaseStringUTFChars(env, jstr, temp); + jstring jstr = (jstring) (*env)->GetObjectArrayElement(env, commands, i); + char *temp = (char *) (*env)->GetStringUTFChars(env, jstr, 0); + argv[i] = malloc(1024); + strcpy(argv[i], temp); + (*env)->ReleaseStringUTFChars(env, jstr, temp); } //execute ffprobe command - char* result = ffprobe_run(argc, argv); + char *result = ffprobe_run(argc, argv); //release memory for (i = 0; i < argc; i++) { - free(argv[i]); + free(argv[i]); } free(argv); diff --git a/app/src/main/cpp/media_player.c b/app/src/main/cpp/media_player.c index 4ad6d98..9fc39ba 100644 --- a/app/src/main/cpp/media_player.c +++ b/app/src/main/cpp/media_player.c @@ -72,23 +72,23 @@ jint JNICALL JNI_OnLoad(JavaVM* vm, void* reserved){ return JNI_VERSION_1_6; } -//初始化输入格式上下文 +//init player int init_input_format_context(MediaPlayer* player, const char* file_name){ - //注册所有组件 + //register all modules av_register_all(); - //分配上下文 + //alloc format context player->format_context = avformat_alloc_context(); - //打开视频文件 + //open the input file if(avformat_open_input(&player->format_context, file_name, NULL, NULL)!=0) { LOGE(TAG, "Couldn't open file:%s\n", file_name); return -1; } - //检索多媒体流信息 + //find the info of all streams if(avformat_find_stream_info(player->format_context, NULL)<0) { LOGE(TAG, "Couldn't find stream information."); return -1; } - //寻找音视频流索引位置 + //find the index of audio and video stream int i; player->video_stream_index = -1; player->audio_stream_index = -1; @@ -114,11 +114,11 @@ int init_input_format_context(MediaPlayer* player, const char* file_name){ return 0; } -//打开音视频解码器 +//open decoder int init_condec_context(MediaPlayer* player){ - //获取codec上下文指针 + //get codec context player->video_codec_context = player->format_context->streams[player->video_stream_index]->codec; - //寻找视频流的解码器 + //find audio and video decoder player->video_codec = avcodec_find_decoder(player->video_codec_context->codec_id); if(player->video_codec == NULL) { LOGE(TAG, "couldn't find video Codec."); @@ -138,25 +138,24 @@ int init_condec_context(MediaPlayer* player){ LOGE(TAG, "Couldn't open audio codec."); return -1; } - // 获取视频宽高 + // width and height player->video_width = player->video_codec_context->width; player->video_height = player->video_codec_context->height; return 0; } -//视频解码 void video_player_prepare(MediaPlayer* player, JNIEnv* env, jobject surface){ - // 获取native window + // get native window player->native_window = ANativeWindow_fromSurface(env, surface); } -//获取当前播放时间 +//get current playing time int64_t get_play_time(MediaPlayer* player){ return (int64_t)(av_gettime() - player->start_time); } /** - * 延迟等待，音视频同步 + * audio and video synchronization */ void player_wait_for_frame(MediaPlayer *player, int64_t stream_time) { pthread_mutex_lock(&player->mutex); @@ -180,7 +179,7 @@ void player_wait_for_frame(MediaPlayer *player, int64_t stream_time) { // and check everything again sleep_time = 500000ll; } - //TODO:等待指定时长 + //TODO: waiting util time out // pthread_cond_timeout_np(&player->cond, &player->mutex, // (unsigned int) (sleep_time / 1000ll)); gettimeofday(&now, NULL); @@ -191,14 +190,12 @@ void player_wait_for_frame(MediaPlayer *player, int64_t stream_time) { pthread_mutex_unlock(&player->mutex); } -//视频解码 +//decode video packet as a frame int decode_video(MediaPlayer* player, AVPacket* packet){ - // 设置native window的buffer大小,可自动拉伸 ANativeWindow_setBuffersGeometry(player->native_window, player->video_width, player->video_height, WINDOW_FORMAT_RGBA_8888); ANativeWindow_Buffer windowBuffer; - //申请内存 player->yuv_frame = av_frame_alloc(); player->rgba_frame = av_frame_alloc(); if(player->rgba_frame == NULL || player->yuv_frame == NULL) { @@ -206,14 +203,13 @@ int decode_video(MediaPlayer* player, AVPacket* packet){ return -1; } - // buffer中数据用于渲染,且格式为RGBA + // get buffer size, the format is RGBA int numBytes=av_image_get_buffer_size(AV_PIX_FMT_RGBA, player->video_width, player->video_height, 1); player->buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t)); av_image_fill_arrays(player->rgba_frame->data, player->rgba_frame->linesize, player->buffer, AV_PIX_FMT_RGBA, player->video_width, player->video_height, 1); - // 由于解码出来的帧格式不是RGBA的,在渲染之前需要进行格式转换 struct SwsContext *sws_ctx = sws_getContext( player->video_width, player->video_height, @@ -227,7 +223,7 @@ int decode_video(MediaPlayer* player, AVPacket* packet){ NULL); int frameFinished; - //对该帧进行解码 + //decode video frame int ret = avcodec_decode_video2(player->video_codec_context, player->yuv_frame, &frameFinished, packet); if(ret < 0){ LOGE(TAG, "avcodec_decode_video2 error..."); @@ -236,27 +232,26 @@ int decode_video(MediaPlayer* player, AVPacket* packet){ if (frameFinished) { // lock native window ANativeWindow_lock(player->native_window, &windowBuffer, 0); - // 格式转换 + // yuv to rgba sws_scale(sws_ctx, (uint8_t const * const *)player->yuv_frame->data, player->yuv_frame->linesize, 0, player->video_height, player->rgba_frame->data, player->rgba_frame->linesize); - // 获取stride uint8_t * dst = windowBuffer.bits; int dstStride = windowBuffer.stride * 4; uint8_t * src = player->rgba_frame->data[0]; int srcStride = player->rgba_frame->linesize[0]; - // 由于window的stride和帧的stride不同,因此需要逐行复制 + // copy data to the target buffer int h; for (h = 0; h < player->video_height; h++) { memcpy(dst + h * dstStride, src + h * srcStride, (size_t) srcStride); } - //计算延迟 + //calculate pts int64_t pts = av_frame_get_best_effort_timestamp(player->yuv_frame); AVStream *stream = player->format_context->streams[player->video_stream_index]; - //转换（不同时间基时间转换） + //convert to real time int64_t time = av_rescale_q(pts, stream->time_base, AV_TIME_BASE_Q); - //音视频帧同步 + //synchronize player_wait_for_frame(player, time); ANativeWindow_unlockAndPost(player->native_window); @@ -264,21 +259,21 @@ int decode_video(MediaPlayer* player, AVPacket* packet){ return 0; } -//音频解码初始化 +//init audio decoder void audio_decoder_prepare(MediaPlayer* player) { player->swrContext = swr_alloc(); - //输入的采样格式 + //input format enum AVSampleFormat in_sample_fmt = player->audio_codec_context->sample_fmt; - //输出采样格式16bit PCM + //output format player->out_sample_fmt = AV_SAMPLE_FMT_S16; - //输入采样率 + //input sampleRate int in_sample_rate = player->audio_codec_context->sample_rate; - //输出采样率 + //output sampleRate player->out_sample_rate = in_sample_rate; - //声道布局（2个声道，默认立体声stereo） + //channel layout (stereo by default) uint64_t in_ch_layout = player->audio_codec_context->channel_layout; - //输出的声道布局（立体声） + //output channel layout uint64_t out_ch_layout = AV_CH_LAYOUT_STEREO; swr_alloc_set_opts(player->swrContext, @@ -286,17 +281,15 @@ void audio_decoder_prepare(MediaPlayer* player) { in_ch_layout, in_sample_fmt, in_sample_rate, 0, NULL); swr_init(player->swrContext); - //输出的声道个数 player->out_channel_nb = av_get_channel_layout_nb_channels(out_ch_layout); } -//音频播放器 void audio_player_prepare(MediaPlayer* player, JNIEnv* env, jclass jthiz){ jclass player_class = (*env)->GetObjectClass(env,jthiz); if(!player_class){ LOGE(TAG, "player_class not found..."); } - //AudioTrack对象 + //get AudioTrack by reflection jmethodID audio_track_method = (*env)->GetMethodID( env,player_class,"createAudioTrack","(II)Landroid/media/AudioTrack;"); if(!audio_track_method){ @@ -305,38 +298,41 @@ void audio_player_prepare(MediaPlayer* player, JNIEnv* env, jclass jthiz){ jobject audio_track = (*env)->CallObjectMethod( env,jthiz,audio_track_method, player->out_sample_rate, player->out_channel_nb); - //调用play方法 jclass audio_track_class = (*env)->GetObjectClass(env, audio_track); jmethodID audio_track_play_mid = (*env)->GetMethodID(env,audio_track_class,"play","()V"); (*env)->CallVoidMethod(env, audio_track, audio_track_play_mid); player->audio_track = (*env)->NewGlobalRef(env, audio_track); - //获取write()方法 player->audio_track_write_mid = (*env)->GetMethodID(env,audio_track_class,"write","([BII)I"); - //16bit 44100 PCM 数据 + //malloc buffer player->audio_buffer = (uint8_t *)av_malloc(MAX_AUDIO_FRAME_SIZE); - //解压缩数据 player->audio_frame = av_frame_alloc(); } -//音频解码 +//audio decode function int decode_audio(MediaPlayer* player, AVPacket* packet){ int got_frame = 0, ret; - //解码 ret = avcodec_decode_audio4(player->audio_codec_context, player->audio_frame, &got_frame, packet); if(ret < 0){ LOGE(TAG, "avcodec_decode_audio4 error..."); return -1; } - //解码一帧成功 + //decode success if(got_frame > 0){ - //音频格式转换 - swr_convert(player->swrContext, &player->audio_buffer, MAX_AUDIO_FRAME_SIZE, (const uint8_t **)player->audio_frame->data, player->audio_frame->nb_samples); - int out_buffer_size = av_samples_get_buffer_size(NULL, player->out_channel_nb, - player->audio_frame->nb_samples, player->out_sample_fmt, 1); - - //音视频帧同步 + //convert audio format + swr_convert(player->swrContext, + &player->audio_buffer, + MAX_AUDIO_FRAME_SIZE, + (const uint8_t **)player->audio_frame->data, + player->audio_frame->nb_samples); + int out_buffer_size = av_samples_get_buffer_size(NULL, + player->out_channel_nb, + player->audio_frame->nb_samples, + player->out_sample_fmt, + 1); + + //synchronize int64_t pts = packet->pts; if (pts != AV_NOPTS_VALUE) { AVStream *stream = player->format_context->streams[player->audio_stream_index]; @@ -349,14 +345,12 @@ int decode_audio(MediaPlayer* player, AVPacket* packet){ (*javaVM)->AttachCurrentThread(javaVM, &env, NULL); jbyteArray audio_sample_array = (*env)->NewByteArray(env,out_buffer_size); jbyte* sample_byte_array = (*env)->GetByteArrayElements(env,audio_sample_array,NULL); - //拷贝缓冲数据 memcpy(sample_byte_array, player->audio_buffer, (size_t) out_buffer_size); - //释放数组 (*env)->ReleaseByteArrayElements(env,audio_sample_array,sample_byte_array,0); - //调用AudioTrack的write方法进行播放 + //call write method of AudioTrack to play (*env)->CallIntMethod(env, player->audio_track, player->audio_track_write_mid, audio_sample_array,0,out_buffer_size); - //释放局部引用 + //release local reference (*env)->DeleteLocalRef(env,audio_sample_array); } } @@ -366,7 +360,6 @@ int decode_audio(MediaPlayer* player, AVPacket* packet){ return 0; } -//初始化队列 void init_queue(MediaPlayer* player, int size){ int i; for (i = 0; i < 2; ++i) { @@ -375,7 +368,6 @@ void init_queue(MediaPlayer* player, int size){ } } -//释放队列 void delete_queue(MediaPlayer* player){ int i; for (i = 0; i < 2; ++i) { @@ -383,7 +375,7 @@ void delete_queue(MediaPlayer* player){ } } -//读取AVPacket线程(生产者) +//the thread of write packet void* write_packet_to_queue(void* arg){ MediaPlayer* player = (MediaPlayer*)arg; AVPacket packet, *pkt = &packet; @@ -394,23 +386,20 @@ void* write_packet_to_queue(void* arg){ break; } if(pkt->stream_index == player->video_stream_index || pkt->stream_index == player->audio_stream_index){ - //根据AVPacket->stream_index获取对应的队列 AVPacketQueue *queue = player->packets[pkt->stream_index]; pthread_mutex_lock(&player->mutex); AVPacket* data = queue_push(queue, &player->mutex, &player->cond); pthread_mutex_unlock(&player->mutex); - //拷贝（间接赋值，拷贝结构体数据） *data = packet; } } } -//音视频解码线程(消费者) +//the thread of decoding void* decode_func(void* arg){ Decoder *decoder_data = (Decoder*)arg; MediaPlayer *player = decoder_data->player; int stream_index = decoder_data->stream_index; - //根据stream_index获取对应的AVPacket队列 AVPacketQueue *queue = player->packets[stream_index]; int ret = 0; @@ -419,9 +408,9 @@ void* decode_func(void* arg){ AVPacket *packet = (AVPacket*)queue_pop(queue, &player->mutex, &player->cond); pthread_mutex_unlock(&player->mutex); - if(stream_index == player->video_stream_index) {//视频流 + if(stream_index == player->video_stream_index) {//video stream ret = decode_video(player, packet); - } else if(stream_index == player->audio_stream_index) {//音频流 + } else if(stream_index == player->audio_stream_index) {//audio stream ret = decode_audio(player, packet); } av_packet_unref(packet); @@ -439,23 +428,21 @@ MEDIA_PLAYER_FUNC(jint, setup, jstring filePath, jobject surface){ if(player == NULL){ return -1; } - //初始化输入格式上下文 ret = init_input_format_context(player, file_name); if(ret < 0){ return ret; } - //初始化音视频解码器 ret = init_condec_context(player); if(ret < 0){ return ret; } - //初始化视频surface + //init surface video_player_prepare( player, env, surface); - //初始化音频相关参数 + //init params of player audio_decoder_prepare(player); - //初始化音频播放器 + //init player audio_player_prepare(player, env, thiz); - //初始化音视频packet队列 + //init queue init_queue(player, PACKET_SIZE); return 0; @@ -465,12 +452,10 @@ MEDIA_PLAYER_FUNC(jint, play){ pthread_mutex_init(&player->mutex, NULL); pthread_cond_init(&player->cond, NULL); - //生产者线程 pthread_create(&player->write_thread, NULL, write_packet_to_queue, (void*)player); sleep(1); player->start_time = 0; - //消费者线程 Decoder data1 = {player, player->video_stream_index}, *decoder_data1 = &data1; pthread_create(&player->video_thread, NULL, decode_func, (void*)decoder_data1); @@ -486,7 +471,6 @@ MEDIA_PLAYER_FUNC(jint, play){ } MEDIA_PLAYER_FUNC(void, release){ - //释放内存以及关闭文件 free(player->audio_track); free(player->audio_track_write_mid); av_free(player->buffer);