C# 通过FFmpegAPI方式拉流
using FFmpeg.AutoGen;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
namespace FFmpegAPI方式拉流
{
public unsafe class tstRtmp
{
///
/// 显示图片委托
///
///
public delegate void ShowBitmap(Bitmap bitmap);
///
/// 执行控制变量
///
bool CanRun;
///
/// 对读取的264数据包进行解码和转换
///
/// 解码完成回调函数
/// 播放地址，也可以是本地文件地址
public unsafe void Start(ShowBitmap show, string url)
{
CanRun = true;
try
{
Console.WriteLine(@"Current directory: " + Environment.CurrentDirectory);
Console.WriteLine(@"Runnung in {0}-bit mode.", Environment.Is64BitProcess ? @"64" : @"32");
//FFmpegDLL目录查找和设置
FFmpegBinariesHelper.RegisterFFmpegBinaries();
#region ffmpeg 初始化
// 初始化注册ffmpeg相关的编码器
ffmpeg.av_register_all();
ffmpeg.avcodec_register_all();
ffmpeg.avformat_network_init();
Console.WriteLine($"FFmpeg version info: {ffmpeg.av_version_info()}");
#endregion
}
catch (Exception ee)
{
}
try
{
//#region ffmpeg 日志
//// 设置记录ffmpeg日志级别
//ffmpeg.av_log_set_level(ffmpeg.AV_LOG_VERBOSE);
//av_log_set_callback_callback logCallback = (p0, level, format, vl) =>
//{
// if (level > ffmpeg.av_log_get_level()) return;
// var lineSize = 1024;
// var lineBuffer = stackalloc byte[lineSize];
// var printPrefix = 1;
// ffmpeg.av_log_format_line(p0, level, format, vl, lineBuffer, lineSize, &printPrefix);
// var line = Marshal.PtrToStringAnsi((IntPtr)lineBuffer);
// Console.Write(line);
//};
//ffmpeg.av_log_set_callback(logCallback);
//#endregion
#region ffmpeg 转码
// 分配音视频格式上下文
var pFormatContext = ffmpeg.avformat_alloc_context();
int error;
//打开流
error = ffmpeg.avformat_open_input(&pFormatContext, url, null, null);
if (error != 0) throw new ApplicationException(GetErrorMessage(error));
// 读取媒体流信息
error = ffmpeg.avformat_find_stream_info(pFormatContext, null);
if (error != 0) throw new ApplicationException(GetErrorMessage(error));
// 这里只是为了打印些视频参数
AVDictionaryEntry* tag = null;
while ((tag = ffmpeg.av_dict_get(pFormatContext->metadata, "", tag, ffmpeg.AV_DICT_IGNORE_SUFFIX)) != null)
{
var key = Marshal.PtrToStringAnsi((IntPtr)tag->key);
var value = Marshal.PtrToStringAnsi((IntPtr)tag->value);
Console.WriteLine($"{key} = {value}");
}
// 从格式化上下文获取流索引
AVStream* pStream = null, aStream;
for (var i = 0; i < pFormatContext->nb_streams; i++)
{
if (pFormatContext->streams[i]->codec->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO)
{
pStream = pFormatContext->streams[i];
}
else if (pFormatContext->streams[i]->codec->codec_type == AVMediaType.AVMEDIA_TYPE_AUDIO)
{
aStream = pFormatContext->streams[i];
}
}
if (pStream == null) throw new ApplicationException(@"Could not found video stream.");
// 获取流的编码器上下文
var codecContext = *pStream->codec;
Console.WriteLine($"codec name: {ffmpeg.avcodec_get_name(codecContext.codec_id)}");
// 获取图像的宽、高及像素格式
var width = codecContext.width;
var height = codecContext.height;
var sourcePixFmt = codecContext.pix_fmt;
// 得到编码器ID
var codecId = codecContext.codec_id;
// 目标像素格式
var destinationPixFmt = AVPixelFormat.AV_PIX_FMT_BGR24;
// 某些264格式codecContext.pix_fmt获取到的格式是AV_PIX_FMT_NONE 统一都认为是YUV420P
if (sourcePixFmt == AVPixelFormat.AV_PIX_FMT_NONE && codecId == AVCodecID.AV_CODEC_ID_H264)
{
sourcePixFmt = AVPixelFormat.AV_PIX_FMT_YUV420P;
}
// 得到SwsContext对象：用于图像的缩放和转换操作
var pConvertContext = ffmpeg.sws_getContext(width, height, sourcePixFmt,
width, height, destinationPixFmt,
ffmpeg.SWS_FAST_BILINEAR, null, null, null);
if (pConvertContext == null) throw new ApplicationException(@"Could not initialize the conversion context.");
//分配一个默认的帧对象:AVFrame
var pConvertedFrame = ffmpeg.av_frame_alloc();
// 目标媒体格式需要的字节长度
var convertedFrameBufferSize = ffmpeg.av_image_get_buffer_size(destinationPixFmt, width, height, 1);
// 分配目标媒体格式内存使用
var convertedFrameBufferPtr = Marshal.AllocHGlobal(convertedFrameBufferSize);
var dstData = new byte_ptrArray4();
var dstLinesize = new int_array4();
// 设置图像填充参数
ffmpeg.av_image_fill_arrays(ref dstData, ref dstLinesize, (byte*)convertedFrameBufferPtr, destinationPixFmt, width, height, 1);
#endregion
#region ffmpeg 解码
// 根据编码器ID获取对应的解码器
var pCodec = ffmpeg.avcodec_find_decoder(codecId);
if (pCodec == null) throw new ApplicationException(@"Unsupported codec.");
var pCodecContext = &codecContext;
if ((pCodec->capabilities & ffmpeg.AV_CODEC_CAP_TRUNCATED) == ffmpeg.AV_CODEC_CAP_TRUNCATED)
pCodecContext->flags |= ffmpeg.AV_CODEC_FLAG_TRUNCATED;
// 通过解码器打开解码器上下文:AVCodecContext pCodecContext
error = ffmpeg.avcodec_open2(pCodecContext, pCodec, null);
if (error < 0) throw new ApplicationException(GetErrorMessage(error));
// 分配解码帧对象：AVFrame pDecodedFrame
var pDecodedFrame = ffmpeg.av_frame_alloc();
// 初始化媒体数据包
var packet = new AVPacket();
var pPacket = &packet;
ffmpeg.av_init_packet(pPacket);
var frameNumber = 0;
while (CanRun)
{
try
{
do
{
// 读取一帧未解码数据
error = ffmpeg.av_read_frame(pFormatContext, pPacket);
Console.WriteLine(pPacket->dts);
if (error == ffmpeg.AVERROR_EOF) break;
if (error < 0) throw new ApplicationException(GetErrorMessage(error));
if (pPacket->stream_index != pStream->index) continue;
// 解码
error = ffmpeg.avcodec_send_packet(pCodecContext, pPacket);
if (error < 0) throw new ApplicationException(GetErrorMessage(error));
// 解码输出解码数据
error = ffmpeg.avcodec_receive_frame(pCodecContext, pDecodedFrame);
} while (error == ffmpeg.AVERROR(ffmpeg.EAGAIN) && CanRun);
if (error == ffmpeg.AVERROR_EOF) break;
if (error < 0) throw new ApplicationException(GetErrorMessage(error));
if (pPacket->stream_index != pStream->index) continue;
Console.WriteLine($@"frame: {frameNumber}");
// YUV->RGB
ffmpeg.sws_scale(pConvertContext, pDecodedFrame->data, pDecodedFrame->linesize, 0, height, dstData, dstLinesize);
}
finally
{
ffmpeg.av_packet_unref(pPacket);//释放数据包对象引用
ffmpeg.av_frame_unref(pDecodedFrame);//释放解码帧对象引用
}
// 封装Bitmap图片
var bitmap = new Bitmap(width, height, dstLinesize[0], PixelFormat.Format24bppRgb, convertedFrameBufferPtr);
// 回调
show(bitmap);
//bitmap.Save(AppDomain.CurrentDomain.BaseDirectory + "\\264\\frame.buffer."+ frameNumber + ".jpg", ImageFormat.Jpeg);
frameNumber++;
}
//播放完置空播放图片
show(null);
#endregion
#region 释放资源
Marshal.FreeHGlobal(convertedFrameBufferPtr);
ffmpeg.av_free(pConvertedFrame);
ffmpeg.sws_freeContext(pConvertContext);
ffmpeg.av_free(pDecodedFrame);
//ffmpeg.avcodec_close(pCodecContext);
ffmpeg.avformat_close_input(&pFormatContext);
ffmpeg.avcodec_close(pCodecContext);
#endregion
}
catch (Exception ee)
{
//throw;
}
finally {
}
}
///
/// 获取ffmpeg错误信息
///
///
///
private static unsafe string GetErrorMessage(int error)
{
var bufferSize = 1024;
var buffer = stackalloc byte[bufferSize];
ffmpeg.av_strerror(error, buffer, (ulong)bufferSize);
var message = Marshal.PtrToStringAnsi((IntPtr)buffer);
return message;
}
public void Stop()
{
CanRun = false;
}
}
}