qt基于FFmPeg+SDL2.0+QOpenGLWidget实现的视频播放器

 #include "videoplayer.h" #include <stdio.h> #include <QDebug> #include <QTimer> #include <qeventloop.h> #define FLUSH_DATA "FLUSH" #define SDL_AUDIO_BUFFER_SIZE 1024 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio /******************************************************** Function: packet_queue_init Description: 队列初始化 Input: *q OutPut: *q Return: Others: Author: Date: *********************************************************/ void packet_queue_init(PacketQueue *q) { memset(q, 0, sizeof(PacketQueue)); /**Create a mutex, initialized unlocked.**/ q->mutex = SDL_CreateMutex(); /**Create a condition variable.**/ q->cond = SDL_CreateCond(); q->size = 0; q->nb_packets = 0; q->first_pkt = NULL; q->last_pkt = NULL; } /******************************************************** Function: packet_queue_put Description: 数据压入队列 Input: *pkt OutPut: *q Return: Others: Author: Date: *********************************************************/ int packet_queue_put(PacketQueue *q, AVPacket *pkt) { AVPacketList *pkt1; if (av_dup_packet(pkt) < 0) { return -1; } pkt1 = (AVPacketList*)av_malloc(sizeof(AVPacketList)); if (!pkt1) { return -1; } pkt1->pkt = *pkt; pkt1->next = NULL; SDL_LockMutex(q->mutex); if (!q->last_pkt) { q->first_pkt = pkt1; } else { q->last_pkt->next = pkt1; } q->last_pkt = pkt1; q->nb_packets++; q->size += pkt1->pkt.size; SDL_CondSignal(q->cond); SDL_UnlockMutex(q->mutex); return 0; } /******************************************************** Function: packet_queue_get Description: 数据出队列 Input: *pkt，block OutPut: *q Return: Others: Author: Date: *********************************************************/ static int packet_queue_get(PacketQueue *q, AVPacket *pkt, int block) { AVPacketList *pkt1; int ret = 0; SDL_LockMutex(q->mutex); for (;;) { pkt1 = q->first_pkt; if (pkt1) { q->first_pkt = pkt1->next; if (!q->first_pkt) { q->last_pkt = NULL; } q->nb_packets--; q->size -= pkt1->pkt.size; *pkt = pkt1->pkt; av_free(pkt1); ret = 1; break; } else if (!block) { ret = 0; break; } else { SDL_CondWait(q->cond, q->mutex); } } SDL_UnlockMutex(q->mutex); return ret; } /******************************************************** Function: packet_queue_flush Description: 清空队列 Input: *q OutPut: *q Return: Others: Author: Date: *********************************************************/ static void packet_queue_flush(PacketQueue *q) { AVPacketList *pkt, *pkt1; SDL_LockMutex(q->mutex); for(pkt = q->first_pkt; pkt != NULL; pkt = pkt1) { pkt1 = pkt->next; if(pkt1->pkt.data != (uint8_t *)"FLUSH") { /**do nothing ?**/ } av_free_packet(&pkt->pkt); av_freep(&pkt); } q->last_pkt = NULL; q->first_pkt = NULL; q->nb_packets = 0; q->size = 0; SDL_UnlockMutex(q->mutex); } /******************************************************** Function: audio_decode_frame Description: 音频解码函数 Input: m_pstVideosState OutPut: pts_ptr Return: Others: Author: Date: *********************************************************/ static int audio_decode_frame(VideoState *m_pstVideosState, double *pts_ptr) { int n; int len1; int len2; int decoded_data_size; int got_frame = 0; int wanted_nb_samples; int resampled_data_size; double pts; int64_t dec_channel_layout; AVPacket *pkt = &m_pstVideosState->audio_pkt; for (;;) { while (m_pstVideosState->audio_pkt_size > 0) { /**判断暂停**/ if (m_pstVideosState->isPause == true) { SDL_Delay(10); continue; } /**为audio_frame分配空间**/ if (!m_pstVideosState->audio_frame) { if (!(m_pstVideosState->audio_frame = av_frame_alloc())) { return AVERROR(ENOMEM); } } else { /**Unreference all the buffers referenced by frame and reset the frame fields.**/ //取消引用帧引用的所有缓冲区并重置帧字段。 av_frame_unref(m_pstVideosState->audio_frame); } /**Decode the audio frame of size pkt->size from pkt->data into audio_frame.**/ //将大小为pkt->size from pkt->data的音频帧解码为音频帧。 len1 = avcodec_decode_audio4(m_pstVideosState->audio_st->codec, m_pstVideosState->audio_frame, &got_frame, pkt); /**解码失败**/ if (len1 < 0) { /**error, skip the frame**/ m_pstVideosState->audio_pkt_size = 0; break; } m_pstVideosState->audio_pkt_data += len1; /**??**/ m_pstVideosState->audio_pkt_size -= len1; /**??**/ /**获取帧失败**/ if (!got_frame) { continue; } /**计算解码出来的桢需要的缓冲大小**/ decoded_data_size = av_samples_get_buffer_size(NULL, m_pstVideosState->audio_frame->channels, m_pstVideosState->audio_frame->nb_samples, (AVSampleFormat)m_pstVideosState->audio_frame->format, 1); /**Channel layout of the audio data**/ dec_channel_layout = (m_pstVideosState->audio_frame->channel_layout && m_pstVideosState->audio_frame->channels == av_get_channel_layout_nb_channels( m_pstVideosState->audio_frame->channel_layout)) ? m_pstVideosState->audio_frame->channel_layout : av_get_default_channel_layout( m_pstVideosState->audio_frame->channels); /**number of audio samples (per channel) described by this frame**/ //此帧描述的音频采样数（每个通道） wanted_nb_samples = m_pstVideosState->audio_frame->nb_samples; if (m_pstVideosState->audio_frame->format != m_pstVideosState->audio_src_fmt || dec_channel_layout != m_pstVideosState->audio_src_channel_layout || m_pstVideosState->audio_frame->sample_rate != m_pstVideosState->audio_src_freq || (wanted_nb_samples != m_pstVideosState->audio_frame->nb_samples && !m_pstVideosState->swr_ctx)) { if (m_pstVideosState->swr_ctx) { swr_free(&m_pstVideosState->swr_ctx); } /**Allocate SwrContext if needed and set/reset common parameters**/ m_pstVideosState->swr_ctx = swr_alloc_set_opts(NULL, m_pstVideosState->audio_tgt_channel_layout, (AVSampleFormat)m_pstVideosState->audio_tgt_fmt, m_pstVideosState->audio_tgt_freq, dec_channel_layout, (AVSampleFormat)m_pstVideosState->audio_frame->format, m_pstVideosState->audio_frame->sample_rate, 0, NULL); if (!m_pstVideosState->swr_ctx || swr_init(m_pstVideosState->swr_ctx) < 0) { //fprintf(stderr,"swr_init() failed\n"); break; } m_pstVide