Converting image to bytes - windows-phone-7

I am using the below code for converting a png image in local path(D:\CURR PROJECT\NewUIChanges\Htmlfile\round1.png)to bytes.I am getting a null execption ie)img stream is null.Plz hep me.
Stream imgStream;
imgStream = Assembly.GetExecutingAssembly().GetManifestResourceStream("NewUIChanges.Htmlfile.round1.png");
byte[] data = new byte[(int)imgStream.Length];
int offset = 0;
while (offset < data.Length)
{
int bytesRead = imgStream.Read(data, offset, data.Length - offset);
if (bytesRead <= 0)
{
throw new EndOfStreamException("Stream wasn't as long as it claimed");
}
offset += bytesRead;
}

Change the build action of the image to Embedded Resource.

This line generating a problem. imgStream is null.
imgStream = Assembly.GetExecutingAssembly().GetManifestResourceStream("NewUIChanges.Htmlfile.round1.png");
Check your image path. Probably is wrong.

Related

Encoding of raw frames (D3D11Texture2D) to an rtsp stream using libav*

I have managed to create a rtsp stream using libav* and directX texture (which I am obtaining from GDI API using Bitblit method). Here's my approach for creating live rtsp stream:
Create output context and stream (skipping the checks here)
avformat_alloc_output_context2(&ofmt_ctx, NULL, "rtsp", rtsp_url); //RTSP
vid_codec = avcodec_find_encoder(ofmt_ctx->oformat->video_codec);
vid_stream = avformat_new_stream(ofmt_ctx,vid_codec);
vid_codec_ctx = avcodec_alloc_context3(vid_codec);
Set codec params
codec_ctx->codec_tag = 0;
codec_ctx->codec_id = ofmt_ctx->oformat->video_codec;
//codec_ctx->codec_type = AVMEDIA_TYPE_VIDEO;
codec_ctx->width = width; codec_ctx->height = height;
codec_ctx->gop_size = 12;
//codec_ctx->gop_size = 40;
//codec_ctx->max_b_frames = 3;
codec_ctx->pix_fmt = target_pix_fmt; // AV_PIX_FMT_YUV420P
codec_ctx->framerate = { stream_fps, 1 };
codec_ctx->time_base = { 1, stream_fps};
if (fctx->oformat->flags & AVFMT_GLOBALHEADER)
{
codec_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
}
Initialize video stream
if (avcodec_parameters_from_context(stream->codecpar, codec_ctx) < 0)
{
Debug::Error("Could not initialize stream codec parameters!");
return false;
}
AVDictionary* codec_options = nullptr;
if (codec->id == AV_CODEC_ID_H264) {
av_dict_set(&codec_options, "profile", "high", 0);
av_dict_set(&codec_options, "preset", "fast", 0);
av_dict_set(&codec_options, "tune", "zerolatency", 0);
}
// open video encoder
int ret = avcodec_open2(codec_ctx, codec, &codec_options);
if (ret<0) {
Debug::Error("Could not open video encoder: ", avcodec_get_name(codec->id), " error ret: ", AVERROR(ret));
return false;
}
stream->codecpar->extradata = codec_ctx->extradata;
stream->codecpar->extradata_size = codec_ctx->extradata_size;
Start streaming
// Create new frame and allocate buffer
AVFrame* AllocateFrameBuffer(AVCodecContext* codec_ctx, double width, double height)
{
AVFrame* frame = av_frame_alloc();
std::vector<uint8_t> framebuf(av_image_get_buffer_size(codec_ctx->pix_fmt, width, height, 1));
av_image_fill_arrays(frame->data, frame->linesize, framebuf.data(), codec_ctx->pix_fmt, width, height, 1);
frame->width = width;
frame->height = height;
frame->format = static_cast<int>(codec_ctx->pix_fmt);
//Debug::Log("framebuf size: ", framebuf.size(), " frame format: ", frame->format);
return frame;
}
void RtspStream(AVFormatContext* ofmt_ctx, AVStream* vid_stream, AVCodecContext* vid_codec_ctx, char* rtsp_url)
{
printf("Output stream info:\n");
av_dump_format(ofmt_ctx, 0, rtsp_url, 1);
const int width = WindowManager::Get().GetWindow(RtspStreaming::WindowId())->GetTextureWidth();
const int height = WindowManager::Get().GetWindow(RtspStreaming::WindowId())->GetTextureHeight();
//DirectX BGRA to h264 YUV420p
SwsContext* conversion_ctx = sws_getContext(width, height, src_pix_fmt,
vid_stream->codecpar->width, vid_stream->codecpar->height, target_pix_fmt,
SWS_BICUBIC | SWS_BITEXACT, nullptr, nullptr, nullptr);
if (!conversion_ctx)
{
Debug::Error("Could not initialize sample scaler!");
return;
}
AVFrame* frame = AllocateFrameBuffer(vid_codec_ctx,vid_codec_ctx->width,vid_codec_ctx->height);
if (!frame) {
Debug::Error("Could not allocate video frame\n");
return;
}
if (avformat_write_header(ofmt_ctx, NULL) < 0) {
Debug::Error("Error occurred when writing header");
return;
}
if (av_frame_get_buffer(frame, 0) < 0) {
Debug::Error("Could not allocate the video frame data\n");
return;
}
int frame_cnt = 0;
//av start time in microseconds
int64_t start_time_av = av_gettime();
AVRational time_base = vid_stream->time_base;
AVRational time_base_q = { 1, AV_TIME_BASE };
// frame pixel data info
int data_size = width * height * 4;
uint8_t* data = new uint8_t[data_size];
// AVPacket* pkt = av_packet_alloc();
while (RtspStreaming::IsStreaming())
{
/* make sure the frame data is writable */
if (av_frame_make_writable(frame) < 0)
{
Debug::Error("Can't make frame writable");
break;
}
//get copy/ref of the texture
//uint8_t* data = WindowManager::Get().GetWindow(RtspStreaming::WindowId())->GetBuffer();
if (!WindowManager::Get().GetWindow(RtspStreaming::WindowId())->GetPixels(data, 0, 0, width, height))
{
Debug::Error("Failed to get frame buffer. ID: ", RtspStreaming::WindowId());
std::this_thread::sleep_for (std::chrono::seconds(2));
continue;
}
//printf("got pixels data\n");
// convert BGRA to yuv420 pixel format
int srcStrides[1] = { 4 * width };
if (sws_scale(conversion_ctx, &data, srcStrides, 0, height, frame->data, frame->linesize) < 0)
{
Debug::Error("Unable to scale d3d11 texture to frame. ", frame_cnt);
break;
}
//Debug::Log("frame pts: ", frame->pts, " time_base:", av_rescale_q(1, vid_codec_ctx->time_base, vid_stream->time_base));
frame->pts = frame_cnt++;
//frame_cnt++;
//printf("scale conversion done\n");
//encode to the video stream
int ret = avcodec_send_frame(vid_codec_ctx, frame);
if (ret < 0)
{
Debug::Error("Error sending frame to codec context! ",frame_cnt);
break;
}
AVPacket* pkt = av_packet_alloc();
//av_init_packet(pkt);
ret = avcodec_receive_packet(vid_codec_ctx, pkt);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
{
//av_packet_unref(pkt);
av_packet_free(&pkt);
continue;
}
else if (ret < 0)
{
Debug::Error("Error during receiving packet: ",AVERROR(ret));
//av_packet_unref(pkt);
av_packet_free(&pkt);
break;
}
if (pkt->pts == AV_NOPTS_VALUE)
{
//Write PTS
//Duration between 2 frames (us)
int64_t calc_duration = (double)AV_TIME_BASE / av_q2d(vid_stream->r_frame_rate);
//Parameters
pkt->pts = (double)(frame_cnt * calc_duration) / (double)(av_q2d(time_base) * AV_TIME_BASE);
pkt->dts = pkt->pts;
pkt->duration = (double)calc_duration / (double)(av_q2d(time_base) * AV_TIME_BASE);
}
int64_t pts_time = av_rescale_q(pkt->dts, time_base, time_base_q);
int64_t now_time = av_gettime() - start_time_av;
if (pts_time > now_time)
av_usleep(pts_time - now_time);
//pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
//pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
//pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
//pkt->pos = -1;
//write frame and send
if (av_interleaved_write_frame(ofmt_ctx, pkt)<0)
{
Debug::Error("Error muxing packet, frame number:",frame_cnt);
break;
}
//Debug::Log("RTSP streaming...");
//sstd::this_thread::sleep_for(std::chrono::milliseconds(1000/20));
//av_packet_unref(pkt);
av_packet_free(&pkt);
}
//av_free_packet(pkt);
delete[] data;
/* Write the trailer, if any. The trailer must be written before you
* close the CodecContexts open when you wrote the header; otherwise
* av_write_trailer() may try to use memory that was freed on
* av_codec_close(). */
av_write_trailer(ofmt_ctx);
av_frame_unref(frame);
av_frame_free(&frame);
printf("streaming thread CLOSED!\n");
}
Now, this allows me to connect to my rtsp server and maintain the connection. However, on the rtsp client side I am getting either gray or single static frame as shown below:
Would appreciate if you can help with following questions:
Firstly, why the stream is not working in spite of continued connection to the server and updating frames?
Video codec. By default rtsp format uses Mpeg4 codec, is it possible to use h264? When I manually set it to AV_CODEC_ID_H264 the program fails at avcodec_open2 with return value of -22.
Do I need to create and allocate new "AVFrame" and "AVPacket" for every frame? Or can I just reuse global variable for this?
Do I need to explicitly define some code for real-time streaming? (Like in ffmpeg we use "-re" flag).
Would be great if you can point out some example code for creating livestream. I have checked following resources:
https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/encode_video.c
streaming FLV to RTMP with FFMpeg using H264 codec and C++ API to flv.js
https://medium.com/swlh/streaming-video-with-ffmpeg-and-directx-11-7395fcb372c4
Update
While test I found that I am able to play the stream using ffplay, while it's getting stuck on VLC player. Here is snapshot on the ffplay log
The basic construct and initialization seems to be okay. Find below responses to your questions
why the stream is not working in spite of continued connection to the server and updating frames?
If you're getting an error or broken stream, you might wanna check into your presentation and decompression timestamps (pts/dts) of your packet.
In your code, I notice that you're taking time_base from video stream object which is not guranteed to be same as codec->time_base value and usually varies depending upon active stream.
AVRational time_base = vid_stream->time_base;
AVRational time_base_q = { 1, AV_TIME_BASE };
Video codec. By default rtsp format uses Mpeg4 codec, is it possible to use h264?
I don't see why not... RTSP is just a protocol for carrying your packets over the network. So you should be able use AV_CODEC_ID_H264 for encoding the stream.
Do I need to create and allocate new "AVFrame" and "AVPacket" for every frame? Or can I just reuse global variable for this?
In libav during encoding process a single packet is used for encoding a video frame, while there can be multiple audio frames in a single packet. I should reference this, but can't seem to find any source at the moment. But anyways the point is you would need to create new packet every time.
Do I need to explicitly define some code for real-time streaming? (Like in ffmpeg we use "-re" flag).
You don't need to add anything else for real time streaming. Although you might wanna implement it to limit the number of frame updates that you pass to encoder and save some performance.
for me the difference between ffplay good capture and VLC bad capture (for UDP packets) was pkt_size=xxx attribute (ffmpeg -re -i test.mp4 -f mpegts udp://127.0.0.1:23000?pkt_size=1316) (VLC open media network tab udp://#:23000:pkt_size=1316). So only if pkt_size is defined (and equal) VLC is able to capture.

Replace Bento4 with libav / ffmpeg

We use Bento4 - a really well designed SDK - to demux mp4 files in .mov containers. Decoding is done by an own codec, so only the raw (intraframe) samples are needed. By now this works pretty straightforward
AP4_Track *test_videoTrack = nullptr;
AP4_ByteStream *input = nullptr;
AP4_Result result = AP4_FileByteStream::Create(filename, AP4_FileByteStream::STREAM_MODE_READ, input);
AP4_File m_file (*input, true);
//
// Read movie tracks, and metadata, find the video track
size_t index = 0;
uint32_t m_width = 0, m_height = 0;
auto item = m_file.GetMovie()->GetTracks().FirstItem();
auto track = item->GetData();
if (track->GetType() == AP4_Track::TYPE_VIDEO)
{
m_width = (uint32_t)((double)test_videoTrack->GetWidth() / double(1 << 16));
m_height = (uint32_t)((double)test_videoTrack->GetHeight() / double(1 << 16));
std::string codec("unknown");
auto sd = track->GetSampleDescription(0);
AP4_String c;
if (AP4_SUCCEEDED(sd->GetCodecString(c)))
{
codec = c.GetChars();
}
// Find and instantiate the decoder
AP4_Sample sample;
AP4_DataBuffer sampleData;
test_videoTrack->ReadSample(0, sample, sampleData);
}
For several reasons we would prefer replacing Bento4 with libav/ffmpeg (mainly because we already have in the project and want to reduce dependencies)
How would we ( preferrably in pseudo-code ) replace the Bento4-tasks done above with libav? Please remember that the used codec is not in the ffmpeg library, so we cannot use the standard ffmpeg decoding examples. Opening the media file simply fails. Without decoder we got no size or any other info so far. What we need would
open the media file
get contained tracks (possibly also audio)
get track size / length info
get track samples by index
It turned out to be very easy:
AVFormatContext* inputFile = avformat_alloc_context();
avformat_open_input(&inputFile, filename, nullptr, nullptr);
avformat_find_stream_info(inputFile, nullptr);
//Get just two streams...First Video & First Audio
int videoStreamIndex = -1, audioStreamIndex = -1;
for (int i = 0; i < inputFile->nb_streams; i++)
{
if (inputFile->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO && videoStreamIndex == -1)
{
videoStreamIndex = i;
}
else if (inputFile->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO && audioStreamIndex == -1)
{
audioStreamIndex = i;
}
}
Now test for the correct codec tag
// get codec id
char ct[64] = {0};
static const char* codec_id = "MPAK";
av_get_codec_tag_string( ct, sizeof(ct),inputFile->streams[videoStreamIndex]->codec->codec_tag);
assert(strncmp( ct , codec_id, strlen(codec_id)) == 0)
I did not know that the sizes are set even before a codec is chosen (or even available).
// lookup size
Size2D mediasize(inputFile->streams[videoStreamIndex]->codec->width, inputFile->streams[videoStreamIndex]->codec->height);
Seeking by frame and unpacking (video) is done like this:
AVStream* s = m_file->streams[videoStreamIndex];
int64_t seek_ts = (int64_t(frame_index) * s->r_frame_rate.den * s->time_base.den) / (int64_t(s->r_frame_rate.num) * s->time_base.num);
av_seek_frame(m_hap_file, videoStreamIndex, seek_ts, AVSEEK_FLAG_ANY);
AVPacket pkt;
av_read_frame(inputFile, &pkt);
Now the packet contains a frame ready to unpack with own decoder.

Covert xamarin.image into base 64 format

I need to Convert a xamarin forms image into a base64 format, Can anyone help me with this?
This is how i've being trying to do it, but it doesent work.
var inputStream = signatureImage.Source.GetValue(UriImageSource.UriProperty);
//Getting Stream as a Memorystream
var signatureMemoryStream = inputStream as MemoryStream;
if (signatureMemoryStream == null)
{
signatureMemoryStream = new MemoryStream();
inputStream.CopyTo(signatureMemoryStream);
}
//Adding memorystream into a byte array
var byteArray = signatureMemoryStream.ToArray();
//Converting byte array into Base64 string
base64String = Convert.ToBase64String(byteArray);
"signatureImage" is the image name.
Once you get your file path , you can use the following code that worked for me.
var stream = file.GetStream();
var bytes = new byte [stream.Length];
await stream.ReadAsync(bytes, 0, (int)stream.Length);
string base64 = System.Convert.ToBase64String(bytes);
I found it here
Image is just a control in Xamarin forms to display the image.
It is not something from which you can get your image byte array out.
You will be better of using the Media Plugin and save it to disk. Then load it via memory stream and convert.
You can also use FFImageLoading. It has 2 methods which can be of use for you :
GetImageAsJpgAsync(int quality = 90, int desiredWidth = 0, int desiredHeight = 0)
GetImageAsPngAsync(int desiredWidth = 0, int desiredHeight = 0)
The SO question - Convert Image into byte array in Xamarin.Forms shows how to do it in Platform specific code here.
The forum thread (Convert Image to byte[]) has a good discussion on why you can't get it from the control.
You can do this as below as well
var base64String = Convert.ToBase64String(File.ReadAllBytes(file.Path))

Images saved with D3DXSaveSurfaceToFile will open in Paint, not Photoshop

I'm using D3DXSaveSurfaceToFile to save windowed Direct3D 9 surfaces to PNG, BMP and JPG files. There are no errors returned from the D3DXSaveSurfaceToFile call and all files open fine in Windows Photo Viewer and Paint. But they will not open in a higher end image editing program such as Paint Shop Pro or Photoshop. The error messages from these programs basically say that the file is corrupted. If I open the files in Paint and then save them in the same file format with a different file name, then they'll open fine in the other programs.
This leads me to believe that D3DXSaveSurfaceToFile is writing out non-standard versions of these file formats. Is there some way I can get this function to write out files that can be opened in programs like Photoshop without the intermediate step of resaving the files in Paint? Or is there another function I should be using that does a better job of saving a Direct3D surfaces to an image?
Take a look at the file in a image meta viewer. What does it tell you?
Unfortunately D3DXSaveSurfaceToFile() isn't the most stable (it's also exceptionally slow). Personally I do something like the below code. It works even on Anti-aliased displays by doing an offscreen render to take the screenshot then getting it into a buffer. It also supports only the most common of the pixel formats. Sorry for any errors in it, pulled it out of an app I used to work on.
You can then, in your code and probably in another thread, then convert said 'bitmap' to anything you like using a variety of different code.
void HandleScreenshot(IDirect3DDevice9* device)
{
DWORD tcHandleScreenshot = GetTickCount();
LPDIRECT3DSURFACE9 pd3dsBack = NULL;
LPDIRECT3DSURFACE9 pd3dsTemp = NULL;
// Grab the back buffer into a surface
if ( SUCCEEDED ( device->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &pd3dsBack) ))
{
D3DSURFACE_DESC desc;
pd3dsBack->GetDesc(&desc);
LPDIRECT3DSURFACE9 pd3dsCopy = NULL;
if (desc.MultiSampleType != D3DMULTISAMPLE_NONE)
{
if (SUCCEEDED(device->CreateRenderTarget(desc.Width, desc.Height, desc.Format, D3DMULTISAMPLE_NONE, 0, FALSE, &pd3dsCopy, NULL)))
{
if (SUCCEEDED(device->StretchRect(pd3dsBack, NULL, pd3dsCopy, NULL, D3DTEXF_NONE)))
{
pd3dsBack->Release();
pd3dsBack = pd3dsCopy;
}
else
{
pd3dsCopy->Release();
}
}
}
if (SUCCEEDED(device->CreateOffscreenPlainSurface(desc.Width, desc.Height, desc.Format, D3DPOOL_SYSTEMMEM, &pd3dsTemp, NULL)))
{
DWORD tmpTimeGRTD = GetTickCount();
if (SUCCEEDED(device->GetRenderTargetData(pd3dsBack, pd3dsTemp)))
{
D3DLOCKED_RECT lockedSrcRect;
if (SUCCEEDED(pd3dsTemp->LockRect(&lockedSrcRect, NULL, D3DLOCK_READONLY | D3DLOCK_NOSYSLOCK | D3DLOCK_NO_DIRTY_UPDATE)))
{
int nSize = desc.Width * desc.Height * 3;
BYTE* pixels = new BYTE[nSize +1];
int iSrcPitch = lockedSrcRect.Pitch;
BYTE* pSrcRow = (BYTE*)lockedSrcRect.pBits;
LPBYTE lpDest = pixels;
LPDWORD lpSrc;
switch (desc.Format)
{
case D3DFMT_A8R8G8B8:
case D3DFMT_X8R8G8B8:
for (int y = desc.Height - 1; y >= 0; y--)
{
lpSrc = reinterpret_cast<LPDWORD>(lockedSrcRect.pBits) + y * desc.Width;
for (unsigned int x = 0; x < desc.Width; x++)
{
*reinterpret_cast<LPDWORD>(lpDest) = *lpSrc;
lpSrc++; // increment source pointer by 1 DWORD
lpDest += 3; // increment destination pointer by 3 bytes
}
}
break;
default:
ZeroMemory(pixels, nSize);
}
pd3dsTemp->UnlockRect();
BITMAPINFOHEADER header;
header.biWidth = desc.Width;
header.biHeight = desc.Height;
header.biSizeImage = nSize;
header.biSize = sizeof(BITMAPINFOHEADER);
header.biPlanes = 1;
header.biBitCount = 3 * 8; // RGB
header.biCompression = 0;
header.biXPelsPerMeter = 0;
header.biYPelsPerMeter = 0;
header.biClrUsed = 0;
header.biClrImportant = 0;
BITMAPFILEHEADER bfh = {0};
bfh.bfType = 0x4d42;
bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
bfh.bfSize = bfh.bfOffBits + nSize;
unsigned int rough_size = sizeof(BITMAPINFOHEADER) + sizeof(BITMAPFILEHEADER) + nSize;
unsigned char* p = new unsigned char[rough_size]
memcpy(p, &bfh, sizeof(BITMAPFILEHEADER));
p += sizeof(BITMAPFILEHEADER);
memcpy(p, &header, sizeof(BITMAPINFOHEADER));
p += sizeof(BITMAPINFOHEADER);
memcpy(p, pixels, nSize);
delete [] pixels;
/**********************************************/
// p now has a full BMP file, write it out here
}
}
pd3dsTemp->Release();
}
pd3dsBack->Release();
}
}
Turns out that it was a combination of a bug in my code and Paint being more forgiving than Photoshop when it comes to reading files. The bug in my code caused the files to be saved with the wrong extension (i.e. Image.bmp was actually saved using D3DXIFF_JPG). When opening a file that contained a JPG image, but had a BMP extension, Photoshop just failed the file. I guess Paint worked since it ignored the file extension and just decoded the file contents.
Looking at a file in an image meta viewer helped me to see the problem.

Audio Unit and Writing to file

I'm creating real-time audio sequencer app on OS X.
Real-time synth part is implemented by using AURenderCallback.
Now I'm making function to write rendered result to Wave File (44100Hz 16bit Stereo).
Format for render-callback function is 44100Hz 32bit float Stereo interleaved.
I'm using ExtAudioFileWrite to write to file.
But ExtAudioFileWrite function returns error code 1768846202;
I searched 1768846202 but I couldn't get information.
Would you give me some hints?
Thank you.
Here is code.
outFileFormat.mSampleRate = 44100;
outFileFormat.mFormatID = kAudioFormatLinearPCM;
outFileFormat.mFormatFlags =
kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
outFileFormat.mBitsPerChannel = 16;
outFileFormat.mChannelsPerFrame = 2;
outFileFormat.mFramesPerPacket = 1;
outFileFormat.mBytesPerFrame =
outFileFormat.mBitsPerChannel / 8 * outFileFormat.mChannelsPerFrame;
outFileFormat.mBytesPerPacket =
outFileFormat.mBytesPerFrame * outFileFormat.mFramesPerPacket;
AudioBufferList *ioList;
ioList = (AudioBufferList*)calloc(1, sizeof(AudioBufferList)
+ 2 * sizeof(AudioBuffer));
ioList->mNumberBuffers = 2;
ioList->mBuffers[0].mNumberChannels = 1;
ioList->mBuffers[0].mDataByteSize = allocByteSize / 2;
ioList->mBuffers[0].mData = ioDataL;
ioList->mBuffers[1].mNumberChannels = 1;
ioList->mBuffers[1].mDataByteSize = allocByteSize / 2;
ioList->mBuffers[1].mData = ioDataR;
...
while (1) {
//Fill buffer by using render callback func.
RenderCallback(self, nil, nil, 0, frames, ioList);
//i want to create one sec file.
if (renderedFrames >= 44100) break;
err = ExtAudioFileWrite(outAudioFileRef, frames , ioList);
if (err != noErr){
NSLog(#"ERROR AT WRITING TO FILE");
goto errorExit;
}
}
Some of the error codes are actually four character strings. The Core Audio book provides a nice function to handle errors.
static void CheckError(OSStatus error, const char *operation)
{
if (error == noErr) return;
char str[20];
// see if it appears to be a 4-char-code
*(UInt32 *)(str + 1) = CFSwapInt32HostToBig(error);
if (isprint(str[1]) && isprint(str[2]) && isprint(str[3]) && isprint(str[4])) {
str[0] = str[5] = '\'';
str[6] = '\0';
} else
// no, format it as an integer
sprintf(str, "%d", (int)error);
fprintf(stderr, "Error: %s (%s)\n", operation, str);
exit(1);
}
Use it like this:
CheckError(ExtAudioFileSetProperty(outputFile,
kExtAudioFileProperty_CodecManufacturer,
sizeof(codec),
&codec), "Setting codec.");
Before you can do any sort of debugging, you probably need to figure out what that error message actually means. Have you tried passing that status code to GetMacOSStatusErrorString() or GetMacOSStatusCommentString()? They aren't documented so well, but they are declared in CoreServices/CarbonCore/Debugging.h.

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