Date: Sun, 4 Jan 2004 23:48:19 +0100
authorSam Lantinga <slouken@libsdl.org>
Mon, 05 Jan 2004 00:57:51 +0000
changeset 773 da0a2ad35bf4
parent 772 5c5656163ebd
child 774 0c3e00cc9580
Date: Sun, 4 Jan 2004 23:48:19 +0100 From: Max Horn Subject: Re: Again Audio CD patch Am 04.01.2004 um 22:38 schrieb Sam Lantinga: > > Okay, I fixed the buffering problems by simply using a 4 second buffer > instead of a 1 second buffer. However, using your code I can't play an > entire CD - the playback stops after the first song. > Found the problem: FSReadFork returns eofErr when the file is finished. However, we check its return value for errors, and if anything but noErr occurs, the reader thread aborts its current iteration. That is bad, because it aborts before it can ever set the flag which tells that the file is over (also, any remaining data which FSRead did return is lost - so you'd not hear about to 4 seconds from the end of the file. Furthermore, the computed data size was 8 bytes to high (I forgot to account for the fact that the size of an (A)IFF chunk always contains the chunk header & size fields, too). This is enough to make it work. However, the end condition is rather fragile, so I tuned some other things to be pessimistic (check for <= 0 instead of == 0, when eofErr is encountered enforce mReadFilePosition == mFileLength). You never know... The attached patch fixes the issue for me.
src/cdrom/macosx/AudioFilePlayer.cpp
src/cdrom/macosx/AudioFileReaderThread.cpp
--- a/src/cdrom/macosx/AudioFilePlayer.cpp	Sun Jan 04 21:32:47 2004 +0000
+++ b/src/cdrom/macosx/AudioFilePlayer.cpp	Mon Jan 05 00:57:51 2004 +0000
@@ -352,7 +352,7 @@
        THROW_RESULT("AudioFilePlayer::OpenFile(): FSSetForkPosition")
 
     // Data size
-    outFileDataSize = chunk.ckSize - ssndData.offset;
+    outFileDataSize = chunk.ckSize - ssndData.offset - 8;
 
     // File format
     mFileDescription.mSampleRate = 44100;
--- a/src/cdrom/macosx/AudioFileReaderThread.cpp	Sun Jan 04 21:32:47 2004 +0000
+++ b/src/cdrom/macosx/AudioFileReaderThread.cpp	Mon Jan 05 00:57:51 2004 +0000
@@ -241,7 +241,7 @@
             dataChunkSize = theItem->mChunkSize;
         
             // this is the exit condition for the thread
-        if (dataChunkSize == 0) {
+        if (dataChunkSize <= 0) {
             theItem->mFinishedReadingData = true;
             continue;
         }
@@ -249,14 +249,9 @@
         char* writePtr = const_cast<char*>(theItem->GetFileBuffer() + 
                                 (theItem->mWriteToFirstBuffer ? 0 : theItem->mChunkSize));
     
-/*
-        printf ("AudioFileReadBytes: theItem=%.8X fileID=%.8X pos=%.8X sz=%.8X flen=%.8X ptr=%.8X\n", 
-            (unsigned int)theItem, (unsigned int)theItem->GetFileID(),
-            (unsigned int)theItem->mReadFilePosition, (unsigned int)dataChunkSize, 
-            (unsigned int)theItem->mFileLength, (unsigned int)writePtr);
-*/            
+            // read data
         result = theItem->Read(writePtr, &dataChunkSize);
-        if (result) {
+        if (result != noErr && result != eofErr) {
             theItem->GetParent().DoNotification(result);
             continue;
         }
@@ -271,7 +266,10 @@
         
         theItem->mWriteToFirstBuffer = !theItem->mWriteToFirstBuffer;   // switch buffers
         
-        theItem->mReadFilePosition += dataChunkSize;        // increment count
+        if (result == eofErr)
+            theItem->mReadFilePosition = theItem->mFileLength;
+        else
+            theItem->mReadFilePosition += dataChunkSize;        // increment count
     }
 }