ffmpeg学习笔记-多线程音视频解码

之前的视频解码仍然存在问题,那就是是在主线程中去完成解码的,会造成线程阻塞,这里将其改为多线程解码,使其主线程不被阻塞

前面介绍了音视频的主线程解码,那样会阻塞主线程,在前面学习了多线程以后,就可以对音频和视频分离开来在子线程里解析了,但这样存在音视频同步的问题了,这里贴出代码,只是提供一种思路,其运行存在大量问题,还需要慢慢解决。例如,退出发生异常,音视频不同步

#include <android/log.h>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <android/native_window.h>
#include <android/native_window_jni.h> #include "com_cj5785_ffmpegvideothread_VideoPlayer.h" #include "include/ffmpeg/libavformat/avformat.h"
#include "include/ffmpeg/libavcodec/avcodec.h"
#include "include/ffmpeg/libswscale/swscale.h"
#include "include/ffmpeg/libswresample/swresample.h"
#include "include/libyuv/libyuv.h" #define LOGI(FORMAT,...) __android_log_print(4,"cj5785",FORMAT,##__VA_ARGS__);
#define LOGE(FORMAT,...) __android_log_print(6,"cj5785",FORMAT,##__VA_ARGS__); #define MAX_STREAM 2
#define VIDEO_STREAM_TYPE 0
#define AUDIO_STREAM_TYPE 1
#define MAX_AUDIO_FRME_SIZE 48000 * 4 typedef struct _Player
{
JavaVM *javaVM;
AVFormatContext *input_format_ctx;
int video_stream_index;
int audio_stream_index;
AVCodecContext *input_codec_ctx[MAX_STREAM];
pthread_t decode_threads[MAX_STREAM];
ANativeWindow* nativeWindow;
SwrContext *swr_ctx;
enum AVSampleFormat in_sample_fmt;
enum AVSampleFormat out_sample_fmt;
int in_sample_rate;
int out_sample_rate;
int out_channel_nb;
jobject audio_track;
jmethodID audio_track_write_mid;
}Player; void init_input_format_ctx(Player *player, const char *input)
{
//注册组件
av_register_all(); AVFormatContext *format_ctx = avformat_alloc_context();
//打开视频文件
if(avformat_open_input(&format_ctx, input, NULL, NULL) != 0)
{
LOGE("%s", "打开文件失败!");
return;
} //获取视频相关信息
if(avformat_find_stream_info(format_ctx, NULL) < 0)
{
LOGE("%s", "获取视频信息失败!");
return;
} //判断输入流的类型
int i = 0;
for (i = 0; i < format_ctx->nb_streams; i++)
{
if(format_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
{
player->video_stream_index = i;
}
else if(format_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
{
player->audio_stream_index = i;
}
} player->input_format_ctx = format_ctx; } void init_codec_context(Player *player,int stream_idx){
AVFormatContext *format_ctx = player->input_format_ctx;
//获取解码器
AVCodecContext *codec_ctx = format_ctx->streams[stream_idx]->codec;
AVCodec *codec = avcodec_find_decoder(codec_ctx->codec_id);
if(codec == NULL){
LOGE("%s","无法解码");
return;
}
//打开解码器
if(avcodec_open2(codec_ctx, codec, NULL) < 0){
LOGE("%s","解码器无法打开");
return;
}
player->input_codec_ctx[stream_idx] = codec_ctx;
} void decode_video_prepare(JNIEnv *env,Player *player,jobject surface){
player->nativeWindow = ANativeWindow_fromSurface(env, surface);
} void decode_video(Player *player,AVPacket *packet)
{
//像素数据(解码数据)
AVFrame *yuv_frame = av_frame_alloc();
AVFrame *rgb_frame = av_frame_alloc();
//绘制时的缓冲区
ANativeWindow_Buffer outBuffer;
AVCodecContext *codec_ctx = player->input_codec_ctx[player->video_stream_index];
int got_frame;
//解码AVPacket->AVFrame
avcodec_decode_video2(codec_ctx, yuv_frame, &got_frame, packet);
//Zero if no frame could be decompressed
//非零,正在解码
if(got_frame){
//lock
//设置缓冲区的属性(宽、高、像素格式)
ANativeWindow_setBuffersGeometry(player->nativeWindow, codec_ctx->width, codec_ctx->height,WINDOW_FORMAT_RGBA_8888);
ANativeWindow_lock(player->nativeWindow,&outBuffer,NULL); //设置rgb_frame的属性(像素格式、宽高)和缓冲区
//rgb_frame缓冲区与outBuffer.bits是同一块内存
avpicture_fill((AVPicture *)rgb_frame, outBuffer.bits, AV_PIX_FMT_RGBA, codec_ctx->width, codec_ctx->height); //YUV->RGBA_8888
I420ToARGB(yuv_frame->data[0],yuv_frame->linesize[0],
yuv_frame->data[2],yuv_frame->linesize[2],
yuv_frame->data[1],yuv_frame->linesize[1],
rgb_frame->data[0], rgb_frame->linesize[0],
codec_ctx->width,codec_ctx->height); //unlock
ANativeWindow_unlockAndPost(player->nativeWindow); usleep(1000 * 16);
} av_frame_free(&yuv_frame);
av_frame_free(&rgb_frame);
} void decode_audio_prepare(Player *player){
SwrContext *swr_ctx = swr_alloc();
AVCodecContext *codec_ctx = player->input_codec_ctx[player->audio_stream_index];
enum AVSampleFormat in_sample_fmt = codec_ctx->sample_fmt;
enum AVSampleFormat out_sample_fmt = AV_SAMPLE_FMT_S16;
int in_sample_rate = codec_ctx->sample_rate;
int out_sample_rate = in_sample_rate;
uint64_t in_ch_layout = codec_ctx->channel_layout;
uint64_t out_ch_layout = AV_CH_LAYOUT_STEREO;
swr_alloc_set_opts(swr_ctx,
out_ch_layout, out_sample_fmt, out_sample_rate,
in_ch_layout, in_sample_fmt, in_sample_rate,
0, NULL);
swr_init(swr_ctx);
int out_channel_nb = av_get_channel_layout_nb_channels(out_ch_layout); player->in_sample_fmt = in_sample_fmt;
player->out_sample_fmt = out_sample_fmt;
player->in_sample_rate = in_sample_rate;
player->out_sample_rate = out_sample_rate;
player->out_channel_nb = out_channel_nb;
player->swr_ctx = swr_ctx;
} void jni_audio_prepare(JNIEnv *env, jobject jobj, Player *player)
{
jclass player_class = (*env)->GetObjectClass(env, jobj);
jmethodID create_audio_track_mid = (*env)->GetMethodID(env, player_class, "createAudioTrack", "(II)Landroid/media/AudioTrack;");
jobject audio_track = (*env)->CallObjectMethod(env, jobj, create_audio_track_mid, player->out_sample_rate, player->out_channel_nb);
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);
jmethodID audio_track_write_mid = (*env)->GetMethodID(env, audio_track_class, "write", "([BII)I"); player->audio_track = (*env)->NewGlobalRef(env, audio_track);
player->audio_track_write_mid = audio_track_write_mid;
} void decode_audio(Player *player, AVPacket *packet)
{
JNIEnv *env = NULL;
JavaVM *javaVM = player->javaVM;
(*javaVM)->AttachCurrentThread(javaVM, &env, NULL);
uint8_t *out_buffer = (uint8_t *)av_malloc(MAX_AUDIO_FRME_SIZE);
AVCodecContext *codec_ctx = player->input_codec_ctx[player->audio_stream_index];
AVFrame *frame = av_frame_alloc();
int got_frame = 0;
avcodec_decode_audio4(codec_ctx, frame, &got_frame, packet);
if(got_frame)
{
swr_convert(player->swr_ctx, &out_buffer, MAX_AUDIO_FRME_SIZE,
(const uint8_t **)frame->data, frame->nb_samples);
int out_buffer_size = av_samples_get_buffer_size(NULL, player->out_channel_nb,
frame->nb_samples ,player->out_sample_fmt, 1);
jbyteArray audio_sample_array = (*env)->NewByteArray(env, out_buffer_size);
jbyte *sample_byte = (*env)->GetByteArrayElements(env, audio_sample_array, NULL);
memcpy(sample_byte, out_buffer, out_buffer_size);
(*env)->ReleaseByteArrayElements(env, audio_sample_array, sample_byte, 0);
(*env)->CallIntMethod(env, player->audio_track, player->audio_track_write_mid,
audio_sample_array, 0, out_buffer_size);
(*env)->DeleteLocalRef(env,audio_sample_array);
(*javaVM)->DetachCurrentThread(javaVM);
usleep(16 * 1000);
}
av_frame_free(&frame);
} void* decode_data(void* arg){
Player *player = (struct Player*)arg;
AVFormatContext *format_ctx = player->input_format_ctx;
//编码数据
AVPacket *packet = (AVPacket *)av_malloc(sizeof(AVPacket));
//6.一阵一阵读取压缩的视频数据AVPacket
int video_frame_count = 0;
while(av_read_frame(format_ctx,packet) >= 0){
if(packet->stream_index == player->video_stream_index)
{
//decode_video(player,packet);
}else if(packet->stream_index == player->audio_stream_index)
{
decode_audio(player,packet);
}
av_free_packet(packet);
}
} JNIEXPORT void JNICALL Java_com_cj5785_ffmpegvideothread_VideoPlayer_play
(JNIEnv *env, jobject jobj, jstring jstr_path, jobject obj_surface)
{
LOGE("%s", "开始"); const char *input_cstr = (*env)->GetStringUTFChars(env, jstr_path, NULL);
Player *player = (Player *)calloc(sizeof(Player), 1); (*env)->GetJavaVM(env,&(player->javaVM)); //初始化封装格式上下文
init_input_format_ctx(player,input_cstr);
int video_stream_index = player->video_stream_index;
int audio_stream_index = player->audio_stream_index;
//获取音视频解码器,并打开
init_codec_context(player,video_stream_index);
init_codec_context(player,audio_stream_index); decode_video_prepare(env, player, obj_surface);
decode_audio_prepare(player);
jni_audio_prepare(env,jobj,player); //创建子线程解码
pthread_create(&(player->decode_threads[video_stream_index]),NULL,decode_data,(void*)player);
pthread_create(&(player->decode_threads[audio_stream_index]),NULL,decode_data,(void*)player); /*ANativeWindow_release(nativeWindow);
av_frame_free(&yuv_frame);
avcodec_close(pCodeCtx);
avformat_free_context(pFormatCtx); (*env)->ReleaseStringUTFChars(env,input_jstr,input_cstr); free(player);*/ }
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