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Rennes Emotion Map 2010-11
19 octobre 2011, par
Mis à jour : Juillet 2013
Langue : français
Type : Texte
Autres articles (95)
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Sur d’autres sites (11800)
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Rust Win32 FFI : User-mode data execution prevention (DEP) violation
28 avril 2022, par TheElixI'm trying to pass a ID3D11Device instance from Rust to a C FFI Library (FFMPEG).


I made this sample code :


pub fn create_d3d11_device(&mut self, device: &mut Box, context: &mut Box) {
 let av_device : Box<avbufferref> = self.alloc(HwDeviceType::D3d11va);
 unsafe {
 let device_context = Box::from_raw(av_device.data as *mut AVHWDeviceContext);
 let mut d3d11_device_context = Box::from_raw(device_context.hwctx as *mut AVD3D11VADeviceContext);
 d3d11_device_context.device = device.as_mut() as *mut _;
 d3d11_device_context.device_context = context.as_mut() as *mut _;
 let avp = Box::into_raw(av_device);
 av_hwdevice_ctx_init(avp);
 self.av_hwdevice = Some(Box::from_raw(avp));
 }
 }
</avbufferref>

On the Rust side the Device does work, but on the C side, when FFMEPG calls
ID3D11DeviceContext_QueryInterfacethe app crashes with the following error :Exception 0xc0000005 encountered at address 0x7ff9fb99ad38: User-mode data execution prevention (DEP) violation at location 0x7ff9fb99ad38

The address is actually the pointer for the lpVtbl of QueryInterface, like seen here :


The disassembly of the address also looks correct (this is done on an another debugging session) :


(lldb) disassemble --start-address 0x00007ffffdf3ad38
 0x7ffffdf3ad38: addb %ah, 0x7ffffd(%rdi,%riz,8)
 0x7ffffdf3ad3f: addb %al, (%rax)
 0x7ffffdf3ad41: movabsl -0x591fffff80000219, %eax
 0x7ffffdf3ad4a: outl %eax, $0xfd


Do you have any pointer to debug this further ?


EDIT : I made a Minimal Reproducion Sample. Interestingly this does not causes a DEP Violation, but simply a Segfault.


On the C side :


int test_ffi(ID3D11Device *device){
 ID3D11DeviceContext *context;
 device->lpVtbl->GetImmediateContext(device, &context);
 if (!context) return 1;
 return 0;
}


On the Rust side :


unsafe fn main_rust(){
 let mut device = None;
 let mut device_context = None;
 let _ = match windows::Win32::Graphics::Direct3D11::D3D11CreateDevice(None, D3D_DRIVER_TYPE_HARDWARE, OtherHinstance::default(), D3D11_CREATE_DEVICE_DEBUG, &[], D3D11_SDK_VERSION, &mut device, std::ptr::null_mut(), &mut device_context) {
 Ok(e) => e,
 Err(e) => panic!("Creation Failed: {}", e)
 };
 let mut device = match device {
 Some(e) => e,
 None => panic!("Creation Failed2")
 };
 let mut f2 : ID3D11Device = transmute_copy(&device); //Transmuting the WinAPI into a bindgen ID3D11Device
 test_ffi(&mut f2);
}


The bindgen build.rs :


extern crate bindgen;

use std::env;
use std::path::PathBuf;

fn main() {
 // Tell cargo to tell rustc to link the system bzip2
 // shared library.
 println!("cargo:rustc-link-lib=ffi_demoLIB");
 println!("cargo:rustc-link-lib=d3d11");

 // Tell cargo to invalidate the built crate whenever the wrapper changes
 println!("cargo:rerun-if-changed=library.h");

 // The bindgen::Builder is the main entry point
 // to bindgen, and lets you build up options for
 // the resulting bindings.
 let bindings = bindgen::Builder::default()
 // The input header we would like to generate
 // bindings for.
 .header("library.h")
 // Tell cargo to invalidate the built crate whenever any of the
 // included header files changed.
 .parse_callbacks(Box::new(bindgen::CargoCallbacks))
 .blacklist_type("_IMAGE_TLS_DIRECTORY64")
 .blacklist_type("IMAGE_TLS_DIRECTORY64")
 .blacklist_type("PIMAGE_TLS_DIRECTORY64")
 .blacklist_type("IMAGE_TLS_DIRECTORY")
 .blacklist_type("PIMAGE_TLS_DIRECTORY")
 // Finish the builder and generate the bindings.
 .generate()
 // Unwrap the Result and panic on failure.
 .expect("Unable to generate bindings");

 // Write the bindings to the $OUT_DIR/bindings.rs file.
 let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
 bindings
 .write_to_file(out_path.join("bindings.rs"))
 .expect("Couldn't write bindings!");
}


The Complete Repo can be found over here : https://github.com/TheElixZammuto/demo-ffi


-
I want to take any Audio from a file and encode it as PCM_ALAW. My Example is a .m4a file to .wav file
22 novembre 2023, par ClockmanI have been working on this for a while now while am generally new to ffmpeg library, I have studied it a bit. The challenge I have that at the point of witting to file I get the following exception.


"Exception thrown at 0x00007FFACA8305B3 (avformat-60.dll) in FfmpegPractice.exe : 0xC0000005 : Access violation writing location 0x0000000000000000.". I understand this means am writing to an uninitialized buffer am unable to discover why this is happening. The exception call stack shows the following


avformat-60.dll!avformat_write_header() C
avformat-60.dll!ff_write_chained() C
avformat-60.dll!ff_write_chained() C
avformat-60.dll!av_write_frame() C
FfmpegPractice.exe!main() Line 215 C++


Some things I have tried


This code is part of a larger project built with CMake but for some reason I could no step into ffmpeg library while debugging, So I recompiled ffmpeg ensured debugging was enabled so I could drill down to the root cause but I still could not step into the ffmpeg library.


I then created a minimal project using visual studio c++ console project and I still could not step into the code.


I have read through many ffmpeg docs and some I could find on the internet and I still could not solve it.


This is the code


#include <iostream>

extern "C" {
#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libswresample></libswresample>swresample.h>
#include <libavutil></libavutil>opt.h>
#include <libavutil></libavutil>audio_fifo.h>
}

using namespace std;

//in audio file
string filename{ "rapid_caller_test.m4a" };
AVFormatContext* pFormatCtx{};
AVCodecContext* pCodecCtx{};
AVStream* pStream{};

//out audio file
string outFilename{ "output.wav" };
AVFormatContext* pOutFormatCtx{ nullptr };
AVCodecContext* pOutCodecCtx{ nullptr };
AVIOContext* pOutIoContext{ nullptr };
const AVCodec* pOutCodec{ nullptr };
AVStream* pOutStream{ nullptr };
const int OUTPUT_CHANNELS = 1;
const int SAMPLE_RATE = 8000;
const int OUT_BIT_RATE = 64000;
uint8_t** convertedSamplesBuffer{ nullptr };
int64_t dstNmbrSamples{ 0 };
int dstLineSize{ 0 };
static int64_t pts{ 0 };

//conversion context;
SwrContext* swr{};

uint32_t i{ 0 };
int audiostream{ -1 };


void cleanUp() 
{
 avcodec_free_context(&pOutCodecCtx);;
 avio_closep(&(pOutFormatCtx)->pb);
 avformat_free_context(pOutFormatCtx);
 pOutFormatCtx = nullptr;
}

int main()
{

/*
* section to setup input file
*/
if (avformat_open_input(&pFormatCtx, filename.data(), nullptr, nullptr) != 0) {
 cout << "could not open file " << filename << endl;
 return -1;
}
if (avformat_find_stream_info(pFormatCtx, nullptr) < 0) {
 cout << "Could not retrieve stream information from file " << filename << endl;
 return -1;
}
av_dump_format(pFormatCtx, 0, filename.c_str(), 0);

for (i = 0; i < pFormatCtx->nb_streams; i++) {
 if (pFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
 audiostream = i;
 break;
 }
}
if (audiostream == -1) {
 cout << "did not find audio stream" << endl;
 return -1;
}

pStream = pFormatCtx->streams[audiostream];
const AVCodec* pCodec{ avcodec_find_decoder(pStream->codecpar->codec_id) };
pCodecCtx = avcodec_alloc_context3(pCodec);
avcodec_parameters_to_context(pCodecCtx, pStream->codecpar);
if (avcodec_open2(pCodecCtx, pCodec, nullptr)) {
 cout << "could not open codec" << endl;
 return -1;
}

/*
* section to set up output file which is a G711 audio
*/
if (avio_open(&pOutIoContext, outFilename.data(), AVIO_FLAG_WRITE)) {
 cout << "could not open out put file" << endl;
 return -1;
}
if (!(pOutFormatCtx = avformat_alloc_context())) {
 cout << "could not create format conext" << endl;
 cleanUp();
 return -1;
}
pOutFormatCtx->pb = pOutIoContext;
if (!(pOutFormatCtx->oformat = av_guess_format(nullptr, outFilename.data(), nullptr))) {
 cout << "could not find output file format" << endl;
 cleanUp();
 return -1;
}
if (!(pOutFormatCtx->url = av_strdup(outFilename.data()))) {
 cout << "could not allocate file name" << endl;
 cleanUp();
 return -1;
}
if (!(pOutCodec = avcodec_find_encoder(AV_CODEC_ID_PCM_ALAW))) {
 cout << "codec not found" << endl;
 cleanUp();
 return -1;
}
if (!(pOutStream = avformat_new_stream(pOutFormatCtx, nullptr))) {
 cout << "could not create new stream" << endl;
 cleanUp();
 return -1;
}
if (!(pOutCodecCtx = avcodec_alloc_context3(pOutCodec))) {
 cout << "could not allocate codec context" << endl;
 return -1;
}
av_channel_layout_default(&pOutCodecCtx->ch_layout, OUTPUT_CHANNELS);
pOutCodecCtx->sample_rate = SAMPLE_RATE;
pOutCodecCtx->sample_fmt = pOutCodec->sample_fmts[0];
pOutCodecCtx->bit_rate = OUT_BIT_RATE;

//setting sample rate for the container
pOutStream->time_base.den = SAMPLE_RATE;
pOutStream->time_base.num = 1;
if (pOutFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
 pOutCodecCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

if (avcodec_open2(pOutCodecCtx, pOutCodec, nullptr)) {
 cout << "could not open output codec" << endl;
 cleanUp();
 return -1;
}
if ((avcodec_parameters_from_context(pOutStream->codecpar, pOutCodecCtx)) < 0) {
 cout << "could not initialize stream parameters" << endl;
} 

AVPacket* packet = av_packet_alloc();

swr = swr_alloc();
swr_alloc_set_opts2(&swr, &pOutCodecCtx->ch_layout, pOutCodecCtx->sample_fmt, pOutCodecCtx->sample_rate,&pCodecCtx->ch_layout, pCodecCtx->sample_fmt, pCodecCtx->sample_rate, 0, nullptr);
swr_init(swr);

int ret{};
int bSize{};
while (av_read_frame(pFormatCtx, packet) >= 0) {
 AVFrame* pFrame = av_frame_alloc();
 AVFrame* pOutFrame = av_frame_alloc();
 if (packet->stream_index == audiostream) {
 ret = avcodec_send_packet(pCodecCtx, packet);
 while (ret >= 0) {
 ret = avcodec_receive_frame(pCodecCtx, pFrame);
 if (ret == AVERROR(EAGAIN))
 continue;
 else if (ret == AVERROR_EOF)
 break;
 dstNmbrSamples = av_rescale_rnd(swr_get_delay(swr, pCodecCtx->sample_rate) + pFrame->nb_samples, pOutCodecCtx->sample_rate, pCodecCtx->sample_rate, AV_ROUND_UP);
 if ((av_samples_alloc_array_and_samples(&convertedSamplesBuffer, &dstLineSize, pOutCodecCtx->ch_layout.nb_channels,dstNmbrSamples, pOutCodecCtx->sample_fmt, 0)) < 0) {
 cout << "coult not allocate samples array and buffer" << endl;
 }
 int channel_samples_count{ 0 };
 channel_samples_count = swr_convert(swr, convertedSamplesBuffer, dstNmbrSamples, (const uint8_t**)pFrame->data, pFrame->nb_samples);
 bSize = av_samples_get_buffer_size(&dstLineSize, pOutCodecCtx->ch_layout.nb_channels, channel_samples_count, pOutCodecCtx->sample_fmt, 0);
 cout << "no of samples is " << channel_samples_count << " the buffer size " << bSize << endl;
 pOutFrame->nb_samples = channel_samples_count;
 av_channel_layout_copy(&pOutFrame->ch_layout, &pOutCodecCtx->ch_layout);
 pOutFrame->format = pOutCodecCtx->sample_fmt;
 pOutFrame->sample_rate = pOutCodecCtx->sample_rate;
 if ((av_frame_get_buffer(pOutFrame, 0)) < 0) {
 cout << "could not allocate output frame samples " << endl;
 av_frame_free(&pOutFrame);
 }
 
 //populate out frame buffer
 av_frame_make_writable(pOutFrame);
 for (int i{ 0 }; i < bSize; i++) {
 pOutFrame->data[0][i] = convertedSamplesBuffer[0][i];
 cout << pOutFrame->data[0][i];
 }
 if (pOutFrame) {
 pOutFrame->pts = pts;
 pts += pOutFrame->nb_samples;
 }
 int res = avcodec_send_frame(pOutCodecCtx, pOutFrame);
 if (res < 0) {
 cout << "error sending frame to encoder" << endl;
 cleanUp();
 return -1;
 }
 //int er = avformat_write_header(pOutFormatCtx,nullptr);
 AVPacket* pOutPacket = av_packet_alloc();
 pOutPacket->time_base.num = 1;
 pOutPacket->time_base.den = 8000;
 if (pOutPacket == nullptr) {
 cout << "unable to allocate packet" << endl;
 }
 while (res >= 0) {
 res = avcodec_receive_packet(pOutCodecCtx, pOutPacket);
 if (res == AVERROR(EAGAIN))
 continue;
 else if (ret == AVERROR_EOF)
 break;
 av_packet_rescale_ts(pOutPacket, pOutCodecCtx->time_base, pOutFormatCtx->streams[0]->time_base);
 //av_dump_format(pOutFormatCtx, 0, outFilename.c_str(), 1);
 if (av_write_frame(pOutFormatCtx, pOutPacket) < 0) {
 cout << "could not write frame" << endl;
 }
 }
 }
}
 av_frame_free(&pFrame);
 av_frame_free(&pOutFrame);
}
if (av_write_trailer(pOutFormatCtx) < 0) {
 cout << "could not write file trailer" << endl;
}
swr_free(&swr);
avcodec_free_context(&pOutCodecCtx);
av_packet_free(&packet);
}
</iostream>

Error/Exception


The exception is thrown when I call


if (av_write_frame(pOutFormatCtx, pOutPacket) < 0) { cout << "could not write frame" << endl; }
I also called this line

//int er = avformat_write_header(pOutFormatCtx,nullptr);

to see if I will get an exception but it did not throw any exception.


I have spent weeks on this issue with no success.
My goal is to take any audio from a file an be able to resample it if need be, and transcode it to PCM_ALAW.
I will appreciate any help I can get.


-
SegFault while freeing nvenc hwdevice_ctx
23 février 2024, par camelCaseFor a project, I created a class encoding the output of an OpenGL
renderbufferobject usingh264_nvenc. Unfortunately, tidying up doesn't work, and the program crashes with a SegFault. The reason is accessing an unaccessable memory region, happening twice in the final lines (see below) when callingav_buffer_unref( &_hwDeviceRefCtx )and implicitely also duringavcodec_free_context( &_pCodecCtx ), but both calls are required for shutting down.

The (in this case relevant)
valgrind-output is

Invalid read of size 8
 at 0x48AD987: UnknownInlinedFun (buffer.c:121)
 by 0x48AD987: UnknownInlinedFun (buffer.c:144)
 by 0x48AD987: av_buffer_unref (buffer.c:139)
 by 0x5D06D7A: avcodec_close (avcodec.c:486)
 by 0x628DD7D: avcodec_free_context (options.c:175)
 by 0x10A863: main (main.cpp:115)
 Address 0x17812700 is 0 bytes inside a block of size 24 free'd
 at 0x484488F: free (vg_replace_malloc.c:985)
 by 0x48AD98F: UnknownInlinedFun (buffer.c:127)
 by 0x48AD98F: UnknownInlinedFun (buffer.c:144)
 by 0x48AD98F: av_buffer_unref (buffer.c:139)
 by 0x48BE098: hwframe_ctx_free (hwcontext.c:240)
 by 0x48AD9A6: UnknownInlinedFun (buffer.c:133)
 by 0x48AD9A6: UnknownInlinedFun (buffer.c:144)
 by 0x48AD9A6: av_buffer_unref (buffer.c:139)
 by 0x5D06D0A: UnknownInlinedFun (decode.c:1261)
 by 0x5D06D0A: avcodec_close (avcodec.c:465)
 by 0x628DD7D: avcodec_free_context (options.c:175)
 by 0x10A863: main (main.cpp:115)
 Block was alloc'd at
 at 0x4849366: posix_memalign (vg_replace_malloc.c:2099)
 by 0x48D9BD5: av_malloc (mem.c:105)
 by 0x48D9DAD: av_mallocz (mem.c:256)
 by 0x48AD8DD: UnknownInlinedFun (buffer.c:44)
 by 0x48AD8DD: av_buffer_create (buffer.c:64)
 by 0x48BDDEB: av_hwdevice_ctx_alloc (hwcontext.c:179)
 by 0x48BDF29: av_hwdevice_ctx_create (hwcontext.c:622)
 by 0x10A482: main (main.cpp:43)

Invalid free() / delete / delete[] / realloc()
 at 0x484488F: free (vg_replace_malloc.c:985)
 by 0x48AD98F: UnknownInlinedFun (buffer.c:127)
 by 0x48AD98F: UnknownInlinedFun (buffer.c:144)
 by 0x48AD98F: av_buffer_unref (buffer.c:139)
 by 0x5D06D7A: avcodec_close (avcodec.c:486)
 by 0x628DD7D: avcodec_free_context (options.c:175)
 by 0x10A863: main (main.cpp:115)
 Address 0x17812700 is 0 bytes inside a block of size 24 free'd
 at 0x484488F: free (vg_replace_malloc.c:985)
 by 0x48AD98F: UnknownInlinedFun (buffer.c:127)
 by 0x48AD98F: UnknownInlinedFun (buffer.c:144)
 by 0x48AD98F: av_buffer_unref (buffer.c:139)
 by 0x48BE098: hwframe_ctx_free (hwcontext.c:240)
 by 0x48AD9A6: UnknownInlinedFun (buffer.c:133)
 by 0x48AD9A6: UnknownInlinedFun (buffer.c:144)
 by 0x48AD9A6: av_buffer_unref (buffer.c:139)
 by 0x5D06D0A: UnknownInlinedFun (decode.c:1261)
 by 0x5D06D0A: avcodec_close (avcodec.c:465)
 by 0x628DD7D: avcodec_free_context (options.c:175)
 by 0x10A863: main (main.cpp:115)
 Block was alloc'd at
 at 0x4849366: posix_memalign (vg_replace_malloc.c:2099)
 by 0x48D9BD5: av_malloc (mem.c:105)
 by 0x48D9DAD: av_mallocz (mem.c:256)
 by 0x48AD8DD: UnknownInlinedFun (buffer.c:44)
 by 0x48AD8DD: av_buffer_create (buffer.c:64)
 by 0x48BDDEB: av_hwdevice_ctx_alloc (hwcontext.c:179)
 by 0x48BDF29: av_hwdevice_ctx_create (hwcontext.c:622)
 by 0x10A482: main (main.cpp:43)


that is also duplicated (due to the calls to
avcodec_free_context()andav_buffer_unref()).

The question is : How can I fix this ?


The (more or less) minimal (not) working example reads


#include <string>

extern "C" {
 #include <libavutil></libavutil>opt.h>
 #include <libavcodec></libavcodec>avcodec.h>
 #include <libavformat></libavformat>avformat.h>
 #include <libavutil></libavutil>hwcontext.h>
 #include <libavutil></libavutil>pixdesc.h>
 #include <libavutil></libavutil>hwcontext_cuda.h>
}

//(former) libx264 encoding based on https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/muxing.c
//update to h264_nvenc with a lot of help from https://stackoverflow.com/questions/49862610/opengl-to-ffmpeg-encode
//and some additional info of https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/vaapi_encode.c

int main() {
 const int _SrcImageWidth=640;
 const int _SrcImageHeight=480;
 
 const AVOutputFormat *_oFmt = nullptr;
 AVFormatContext *_oFmtCtx = nullptr;
 
 const AVCodec *_pCodec = nullptr;
 AVCodecContext *_pCodecCtx = nullptr;
 
 AVFrame* _frame;
 AVPacket* _packet;
 AVStream* _stream;
 
 AVBufferRef *_hwDeviceRefCtx = nullptr;
 const CUcontext* _cudaCtx;
 
 const std::string _OutFileName = "output.mkv";
 
 //constructor part
 int ret;

 //output format context 
 avformat_alloc_output_context2( &_oFmtCtx, nullptr, nullptr, _OutFileName.c_str() );
 _oFmt = _oFmtCtx->oformat;

 //hardware format context
 ret = av_hwdevice_ctx_create( &_hwDeviceRefCtx, AV_HWDEVICE_TYPE_CUDA, "NVIDIA GeForce RTX 4070", nullptr, 0 );

 //hardware frame context for device buffer allocation
 AVBufferRef* hwFrameRefCtx = av_hwframe_ctx_alloc( _hwDeviceRefCtx );
 AVHWFramesContext* hwFrameCtx = (AVHWFramesContext*) (hwFrameRefCtx->data);
 hwFrameCtx->width = _SrcImageWidth;
 hwFrameCtx->height = _SrcImageHeight;
 hwFrameCtx->sw_format = AV_PIX_FMT_0BGR32;
 hwFrameCtx->format = AV_PIX_FMT_CUDA;
 hwFrameCtx->device_ref = _hwDeviceRefCtx;
 hwFrameCtx->device_ctx = (AVHWDeviceContext*) _hwDeviceRefCtx->data;

 ret = av_hwframe_ctx_init( hwFrameRefCtx );

 //get cuda context
 const AVHWDeviceContext* hwDeviceCtx = (AVHWDeviceContext*)(_hwDeviceRefCtx->data);
 const AVCUDADeviceContext* cudaDeviceCtx = (AVCUDADeviceContext*)(hwDeviceCtx->hwctx);
 _cudaCtx = &(cudaDeviceCtx->cuda_ctx);

 //codec context
 _pCodec = avcodec_find_encoder_by_name( "h264_nvenc" );

 _packet = av_packet_alloc();

 _stream = avformat_new_stream( _oFmtCtx, nullptr );
 _stream->id = _oFmtCtx->nb_streams - 1;
 _pCodecCtx = avcodec_alloc_context3( _pCodec );

 _pCodecCtx->qmin = 18;
 _pCodecCtx->qmax = 20;
 _pCodecCtx->width = _SrcImageWidth;
 _pCodecCtx->height = _SrcImageHeight;
 _pCodecCtx->framerate = (AVRational) {25,1};
 _pCodecCtx->time_base = (AVRational) {1,25};
 _stream->time_base = _pCodecCtx->time_base;
 _pCodecCtx->gop_size = 12; //I-Frame every at most 12 frames
 _pCodecCtx->max_b_frames = 2;
 _pCodecCtx->pix_fmt = AV_PIX_FMT_CUDA; //required to use renderbuffer as src
 _pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
 _pCodecCtx->sw_pix_fmt = AV_PIX_FMT_0BGR32; 
 _pCodecCtx->hw_device_ctx = _hwDeviceRefCtx;
 _pCodecCtx->hw_frames_ctx = av_buffer_ref( hwFrameRefCtx );
 av_opt_set(_pCodecCtx->priv_data, "preset", "p7", 0);
 av_opt_set(_pCodecCtx->priv_data, "rc", "vbr", 0);
 if( _oFmtCtx->oformat->flags & AVFMT_GLOBALHEADER ) {
 _pCodecCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
 }

 ret = avcodec_open2( _pCodecCtx, _pCodec, nullptr );
 avcodec_parameters_from_context( _stream->codecpar, _pCodecCtx );

 if (!(_oFmtCtx->oformat->flags & AVFMT_NOFILE)) {
 ret = avio_open(&_oFmtCtx->pb, _OutFileName.c_str(), AVIO_FLAG_WRITE);
 }
 ret = avformat_write_header( _oFmtCtx, nullptr );

 //use hardware frame from above
 _frame = av_frame_alloc();
 ret = av_hwframe_get_buffer( _pCodecCtx->hw_frames_ctx, _frame, 0 );
 _frame->pts = 1;

 av_buffer_unref( &hwFrameRefCtx );

 //destructor part
 av_frame_free( &_frame );
 av_packet_free( &_packet );

 av_write_trailer( _oFmtCtx );
 avio_closep( &_oFmtCtx->pb );

 avformat_free_context( _oFmtCtx );

 avcodec_free_context( &_pCodecCtx );
 av_buffer_unref( &_hwDeviceRefCtx );

 return 0;
}
</string>

and compiles with (linux user)


g++ -lavutil -lavformat -lavcodec -lz -lavutil -lswscale -lswresample -lm -ggdb3 -I/opt/cuda/include main.cpp


Thanks in advance !


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