Hey. Im trying to build a video frame by frame by passing frames to FFmpeg via a pipe (in this case an anonymous pipe). Operating System: Windows 10 My language is C++. Trying to follow this Python tutorial : http://zulko.github.io/blog/2013/09/27/read-and-write-video-frames-in-python... Everything is working as expected, except the closing of the pipe. I would assume that when closing my write end of the pipe, FFmpeg should finish the video and exit. But it doesn't. I first tried using the commandline and receiving from STDIN (just write some crappy values), but can't get the pipe to close properly with EOF (STRG+Z). Typing EOF multiple times finally closes and I get an output video. My target is to achieve this using UnrealEngine. But it can't make FFmpeg finish up. So I wrote my own little program that create gray values for the frames. The result is the same, FFmpeg does not finish up. Here is the whole program: #include "stdafx.h" //// stdafx.h //#include "targetver.h" //#include <stdio.h> //#include <tchar.h> //#include <iostream> #include "Windows.h" #include <cstdlib> using namespace std; bool WritePipe(void* WritePipe, const UINT8 *const Buffer, const UINT32 Length) { if (WritePipe == nullptr || Buffer == nullptr || Length == 0) { cout << __FUNCTION__ << ": Some input is useless"; return false; } // Write to pipe UINT32 BytesWritten = 0; UINT8 newline = '\n'; bool bIsWritten = WriteFile(WritePipe, Buffer, Length, (::DWORD*)&BytesWritten, nullptr); cout << __FUNCTION__ << " Bytes written to pipe " << BytesWritten << endl; //bIsWritten = WriteFile(WritePipe, &newline, 1, (::DWORD*)&BytesWritten, nullptr); // Do we need this? Actually this should destroy the image. FlushFileBuffers(WritePipe); // Do we need this? return bIsWritten; } #define PIXEL 80 // must be multiple of 8. Otherwise we get warning: Bytes are not aligned int main() { HANDLE PipeWriteEnd = nullptr; HANDLE PipeReadEnd = nullptr; { // create us a pipe for inter process communication SECURITY_ATTRIBUTES Attr = { sizeof(SECURITY_ATTRIBUTES), NULL, true }; if (!CreatePipe(&PipeReadEnd, &PipeWriteEnd, &Attr, 0)) { cout << "Could not create pipes" << ::GetLastError() << endl; system("Pause"); return 0; } } // Setup the variables needed for CreateProcess // initialize process attributes SECURITY_ATTRIBUTES Attr; Attr.nLength = sizeof(SECURITY_ATTRIBUTES); Attr.lpSecurityDescriptor = NULL; Attr.bInheritHandle = true; // initialize process creation flags UINT32 CreateFlags = NORMAL_PRIORITY_CLASS; CreateFlags |= CREATE_NEW_CONSOLE; // initialize window flags UINT32 dwFlags = 0; UINT16 ShowWindowFlags = SW_HIDE; if (PipeWriteEnd != nullptr || PipeReadEnd != nullptr) { dwFlags |= STARTF_USESTDHANDLES; } // initialize startup info STARTUPINFOA StartupInfo = { sizeof(STARTUPINFO), NULL, NULL, NULL, (::DWORD)CW_USEDEFAULT, (::DWORD)CW_USEDEFAULT, (::DWORD)CW_USEDEFAULT, (::DWORD)CW_USEDEFAULT, (::DWORD)0, (::DWORD)0, (::DWORD)0, (::DWORD)dwFlags, ShowWindowFlags, 0, NULL, HANDLE(PipeReadEnd), HANDLE(nullptr), HANDLE(nullptr) }; LPSTR ffmpegURL = "\"FFMPEGDIRECTORY\ffmpeg.exe\" -y -loglevel verbose -f rawvideo -vcodec rawvideo -framerate 1 -video_size 80x80 -pixel_format rgb24 -i - -vcodec mjpeg -framerate 1/4 -an \"OUTPUTDIR\sometest.mp4\""; // Finally create the process PROCESS_INFORMATION ProcInfo; if (!CreateProcessA(NULL, ffmpegURL, &Attr, &Attr, true, (::DWORD)CreateFlags, NULL, NULL, &StartupInfo, &ProcInfo)) { cout << "CreateProcess failed " << ::GetLastError() << endl; } CloseHandle(ProcInfo.hThread); // note sure if this is needed system("pause"); { // Create images and write to pipe #define MYARRAYSIZE (PIXEL*PIXEL*3) // each pixel has 3 bytes UINT8* Bitmap = new UINT8[MYARRAYSIZE]; for (INT32 outerLoopIndex = 50; outerLoopIndex >= 0; --outerLoopIndex) // frame loop { for (INT32 innerLoopIndex = MYARRAYSIZE - 1; innerLoopIndex >= 0; --innerLoopIndex) // create the pixels for each frame { Bitmap[innerLoopIndex] = (UINT8)(outerLoopIndex * 4); // some gray color } system("pause"); if (!WritePipe(PipeWriteEnd, Bitmap, MYARRAYSIZE)) { cout << "Failed writing to pipe" << endl; } } // Done sending images. Tell the other process. IS THIS NEEDED? HOW TO TELL FFmpeg WE ARE DONE? UINT8 endOfFile = 0xFF; // EOF = -1 == 1111 1111 for uint8 if (!WritePipe(PipeWriteEnd, &endOfFile, 1)) { cout << "Failed writing to pipe" << endl; } delete Bitmap; } system("Pause"); // clean stuff up // We do not want to destroy the read end of the pipe as that belongs to FFmpeg //if (PipeReadEnd != NULL && PipeReadEnd != INVALID_HANDLE_VALUE) //{ // ::CloseHandle(PipeReadEnd); //} if (PipeWriteEnd != NULL && PipeWriteEnd != INVALID_HANDLE_VALUE) { ::CloseHandle(PipeWriteEnd); } return 0; } And here the whole output from FFmpeg ffmpeg version 3.4.1 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 7.2.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx libavutil 55. 78.100 / 55. 78.100 libavcodec 57.107.100 / 57.107.100 libavformat 57. 83.100 / 57. 83.100 libavdevice 57. 10.100 / 57. 10.100 libavfilter 6.107.100 / 6.107.100 libswscale 4. 8.100 / 4. 8.100 libswresample 2. 9.100 / 2. 9.100 libpostproc 54. 7.100 / 54. 7.100 [rawvideo @ 000002207d1220a0] max_analyze_duration 5000000 reached at 5000000 microseconds st:0 Input #0, rawvideo, from 'pipe:': Duration: N/A, start: 0.000000, bitrate: 153 kb/s Stream #0:0: Video: rawvideo, 1 reference frame (RGB[24] / 0x18424752), rgb24, 80x80, 153 kb/s, 1 fps, 1 tbr, 1 tbn, 1 tbc Stream mapping: Stream #0:0 -> #0:0 (rawvideo (native) -> mjpeg (native)) [graph 0 input from stream 0:0 @ 000002207d1966e0] w:80 h:80 pixfmt:rgb24 tb:1/1 fr:1/1 sar:0/1 sws_param:flags=2 [auto_scaler_0 @ 000002207d130280] w:iw h:ih flags:'bicubic' interl:0 [format @ 000002207d12fd80] auto-inserting filter 'auto_scaler_0' between the filter 'Parsed_null_0' and the filter 'format' [swscaler @ 000002207d19a000] deprecated pixel format used, make sure you did set range correctly [auto_scaler_0 @ 000002207d130280] w:80 h:80 fmt:rgb24 sar:0/1 -> w:80 h:80 fmt:yuvj444p sar:0/1 flags:0x4 Output #0, mp4, to 'c:/users/vr3/Documents/Guenni/sometest.mp4': Metadata: encoder : Lavf57.83.100 Stream #0:0: Video: mjpeg, 1 reference frame (mp4v / 0x7634706D), yuvj444p(pc), 80x80, q=2-31, 200 kb/s, 1 fps, 16384 tbn, 1 tbc Metadata: encoder : Lavc57.107.100 mjpeg Side data: cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1 frame= 50 fps= 14 q=1.6 size= 0kB time=00:00:49.00 bitrate= 0.0kbits/s speed=13.3x As you can see on the output of FFmpeg, there are 50 frames writte. Everything as should be. But how to tell FFmpeg the pipe is closed, there will not come any more frames.