ffmepg C++ 编码后 混合 aac h264 数据流 到文件 pts 音视频同步
时间: 2024-03-28 22:36:53 浏览: 300
simplest_ffmpeg_video_encoder.zip_H.264_YUV 264编码_ffmpeg encode_
您好,针对您的问题,我可以给出如下思路:
1. 使用FFmpeg的C++ API来编码H264和AAC数据流,并将它们混合在一起。
2. 对于每个视频帧和音频帧,使用PTS(Presentation Time Stamp)来保证它们的时间戳是正确的。
3. 将编码后的H264和AAC数据流写入一个文件中,同时确保它们的时间戳是同步的。
下面是一个简单的示例代码,仅供参考:
```
#include <iostream>
#include <string>
#include <vector>
#include <chrono>
#include <thread>
extern "C" {
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libavutil/opt.h>
#include <libavutil/timestamp.h>
#include <libavutil/audio_fifo.h>
}
#define AUDIO_SAMPLE_RATE 48000
#define AUDIO_CHANNELS 2
#define AUDIO_FORMAT AV_SAMPLE_FMT_FLT
#define AUDIO_BITRATE 128000
using namespace std;
int main(int argc, char* argv[])
{
// Initialize FFmpeg
av_register_all();
avcodec_register_all();
// Open video output file
AVFormatContext* out_ctx;
avformat_alloc_output_context2(&out_ctx, NULL, NULL, "output.mp4");
AVStream* video_stream = avformat_new_stream(out_ctx, NULL);
AVStream* audio_stream = avformat_new_stream(out_ctx, NULL);
// Configure video stream
AVCodec* video_codec = avcodec_find_encoder(AV_CODEC_ID_H264);
AVCodecContext* video_ctx = avcodec_alloc_context3(video_codec);
video_ctx->bit_rate = 400000;
video_ctx->width = 640;
video_ctx->height = 480;
video_ctx->time_base = { 1, 25 };
video_ctx->gop_size = 10;
video_ctx->max_b_frames = 1;
avcodec_open2(video_ctx, video_codec, NULL);
avcodec_parameters_from_context(video_stream->codecpar, video_ctx);
video_stream->time_base = video_ctx->time_base;
// Configure audio stream
AVCodec* audio_codec = avcodec_find_encoder(AV_CODEC_ID_AAC);
AVCodecContext* audio_ctx = avcodec_alloc_context3(audio_codec);
audio_ctx->sample_rate = AUDIO_SAMPLE_RATE;
audio_ctx->channels = AUDIO_CHANNELS;
audio_ctx->sample_fmt = AUDIO_FORMAT;
audio_ctx->bit_rate = AUDIO_BITRATE;
audio_ctx->time_base = { 1, AUDIO_SAMPLE_RATE };
avcodec_open2(audio_ctx, audio_codec, NULL);
avcodec_parameters_from_context(audio_stream->codecpar, audio_ctx);
audio_stream->time_base = audio_ctx->time_base;
// Open output file
avio_open(&out_ctx->pb, "output.mp4", AVIO_FLAG_WRITE);
// Write header to output file
avformat_write_header(out_ctx, NULL);
// Encode and write frames to output file
for (int i = 0; i < 100; i++) {
// Encode video frame
AVFrame* video_frame = av_frame_alloc();
video_frame->width = video_ctx->width;
video_frame->height = video_ctx->height;
video_frame->format = video_ctx->pix_fmt;
av_frame_get_buffer(video_frame, 0);
// Fill video frame with data...
avcodec_send_frame(video_ctx, video_frame);
AVPacket video_pkt;
av_init_packet(&video_pkt);
avcodec_receive_packet(video_ctx, &video_pkt);
video_pkt.stream_index = video_stream->index;
video_pkt.pts = i * video_ctx->time_base.den / (video_ctx->time_base.num * 25);
video_pkt.dts = video_pkt.pts;
av_interleaved_write_frame(out_ctx, &video_pkt);
av_packet_unref(&video_pkt);
av_frame_free(&video_frame);
// Encode audio frame
AVFrame* audio_frame = av_frame_alloc();
audio_frame->sample_rate = audio_ctx->sample_rate;
audio_frame->channels = audio_ctx->channels;
audio_frame->format = audio_ctx->sample_fmt;
av_frame_get_buffer(audio_frame, 0);
// Fill audio frame with data...
avcodec_send_frame(audio_ctx, audio_frame);
AVPacket audio_pkt;
av_init_packet(&audio_pkt);
avcodec_receive_packet(audio_ctx, &audio_pkt);
audio_pkt.stream_index = audio_stream->index;
audio_pkt.pts = i * audio_ctx->time_base.den / AUDIO_SAMPLE_RATE;
audio_pkt.dts = audio_pkt.pts;
av_interleaved_write_frame(out_ctx, &audio_pkt);
av_packet_unref(&audio_pkt);
av_frame_free(&audio_frame);
// Sleep for a while to simulate real-time processing
this_thread::sleep_for(chrono::milliseconds(40));
}
// Write trailer to output file
av_write_trailer(out_ctx);
// Close output file
avio_close(out_ctx->pb);
avformat_free_context(out_ctx);
// Cleanup FFmpeg
avcodec_free_context(&video_ctx);
avcodec_free_context(&audio_ctx);
return 0;
}
```
在上述示例代码中,我们先初始化了FFmpeg,并创建了一个输出文件。然后,我们分别配置了视频流和音频流的编码参数,并将它们添加到输出文件中。接下来,我们编码并写入了100个视频帧和音频帧,并使用PTS保证它们的时间戳是正确的。最后,我们写入了输出文件的尾部,并关闭了输出文件。
请注意,上述示例代码仅供参考,您需要根据自己的实际需求进行修改和优化。
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