int RiffFile::open(const char* path)
{
// Open the file
mpFile = fopen(path, "rb");
if(!mpFile)
{
return 1; // error
}
RiffChunkHeader root_chunk;
// Read the header info for the root chunk.
if (fread(&root_chunk, sizeof(UInt32), 3, mpFile) != 3)
{
return 1; // error
}
root_chunk.chunkSize -= sizeof(UInt32); // root chunk has an extra format code in header.
// Save the location of the root data segment.
root_chunk.dataStart = ftell(mpFile);
if(root_chunk.chunkId != STR2FOURCC("RIFF") || root_chunk.dataStart < 0)
{
return 1; // error
}
mChunkStack.push_back(root_chunk);
return 0; // success
}
int WaveFile::open(const char *path)
{
int status = RiffFile::open(path);
if(status != 0)
return status;
char s[5];
FOURCC2STR(formatCode(), s);
printf("type = %s\n", s);
if(formatCode() != STR2FOURCC("WAVE"))
{
return 1; // error
}
// Jump into the "fmt " chunk
if(push(STR2FOURCC("fmt ")))
{
memset(&mHeader, 0, sizeof(mHeader));
UInt32 fmtSize = chunkSize();
if(RiffFile::readData(&mHeader, fmtSize) != fmtSize)
{
return 1; // error
}
assert(mHeader.formatTag == 1); // only uncompressed files are supported
// Some writers put a bad block align and/or avgBytesPerSecond value.
// Let's recalculate it.
mHeader.bytesPerFrame = mHeader.bitsPerSample / 8 * mHeader.numChannels;
mHeader.averageBytesPerSecond = mHeader.bytesPerFrame * mHeader.samplesPerSecond;
}
// Jump out of the "fmt " chunk
pop();
// Jump into the "data" chunk
if(!push(STR2FOURCC("data")))
{
return 1; // error, couldn't find the data chunk
}
return 0; // success
}
bool RiffFile::push(UInt32 chunkId)
{
long start_pos = ftell(mpFile);
RiffChunkHeader parent_chunk = mChunkStack.back();
// Seek to start of current chunk, and iterate over children looking for desired chunk id.
fseek(mpFile, parent_chunk.dataStart, SEEK_SET);
RiffChunkHeader child_chunk;// = (RiffChunkHeader *)malloc(sizeof(RiffChunkHeader));
child_chunk.formatCode = 0;
long parent_end = parent_chunk.dataStart + parent_chunk.chunkSize;
while(!feof(mpFile) && ftell(mpFile) < parent_end)
{
// Read the full header of this child.
if(fread(&child_chunk, sizeof(UInt32), 2, mpFile) != 2)
break; // something went wrong. bail.
if(child_chunk.chunkId == STR2FOURCC("RIFF") || child_chunk.chunkId == STR2FOURCC("LIST"))
{
if(fread(&child_chunk.formatCode, sizeof(UInt32), 1, mpFile) != 1)
break;
child_chunk.chunkSize -= sizeof(UInt32);
}
child_chunk.dataStart = ftell(mpFile);
// If this child is the one we're looking for, push it and return.
if(child_chunk.chunkId == chunkId)
{
mChunkStack.push_back(child_chunk);
fseek(mpFile, mChunkStack.back().dataStart, SEEK_SET);
return true;
}
// Find the start of our next sibling.
long next_sibling_start = child_chunk.dataStart + child_chunk.chunkSize;
next_sibling_start += next_sibling_start % 2; // word align
fseek(mpFile, next_sibling_start, SEEK_SET);
}
clearerr(mpFile);
fseek(mpFile, start_pos, SEEK_SET);
return false;
}
