Fix-duration (#99)

* fix wav file duration #95

* fix mp3 file duration #95

* fix: mark file not vbr when header is start with "Info"

* fix: fallback for waveHeader.averageBytePerSecond

* test: correct riff duration

Author: subframe7536

src/mpeg/mpegAudioHeader.ts

@@ -90,7 +90,7 @@ export default class MpegAudioHeader implements IAudioCodec {
         file.seek(position + XingHeader.xingHeaderOffset(header.version, header.channelMode));
 
         const xingData = file.readBlock(16);
-        if (xingData.length === 16 && xingData.startsWith(XingHeader.FILE_IDENTIFIER)) {
+        if (xingData.length === 16 && (xingData.startsWith(XingHeader.FILE_IDENTIFIER) || xingData.startsWith(XingHeader.FILE_IDENTIFIER_INFO))) {
             header._xingHeader = XingHeader.fromData(xingData);
         }
 

src/mpeg/xingHeader.ts

@@ -11,6 +11,7 @@ export default class XingHeader {
      * Identifier that appears in a file to indicate the start of a Xing header.
      */
     public static readonly FILE_IDENTIFIER = ByteVector.fromString("Xing", StringType.Latin1).makeReadOnly();
+    public static readonly FILE_IDENTIFIER_INFO = ByteVector.fromString("Info", StringType.Latin1).makeReadOnly();
 
     /**
      * An empty an unset Xing header
@@ -48,8 +49,10 @@ export default class XingHeader {
     public static fromData(data: ByteVector): XingHeader {
         Guards.truthy(data, "data");
 
+        const isInfoHeader = data.startsWith(XingHeader.FILE_IDENTIFIER_INFO);
+
         // Check to see if a valid Xing header is available
-        if (!data.startsWith(XingHeader.FILE_IDENTIFIER)) {
+        if (!data.startsWith(XingHeader.FILE_IDENTIFIER) && !isInfoHeader) {
             throw new CorruptFileError("Not a valid Xing header");
         }
 
@@ -69,7 +72,7 @@ export default class XingHeader {
             header._totalSize = 0;
         }
 
-        header._isPresent = true;
+        header._isPresent = !isInfoHeader;
 
         return header;
     }

src/riff/riffFile.ts

@@ -379,8 +379,9 @@ export default class RiffFile extends File {
                 }
 
                 codecs = [waveHeader];
-                durationMilliseconds = dataChunk.originalDataSize * 8000
-                    / waveHeader.bitsPerSample / waveHeader.audioSampleRate;
+                durationMilliseconds = waveHeader.averageBytesPerSecond
+                    ? dataChunk.originalDataSize * 1000 / waveHeader.averageBytesPerSecond
+                    : dataChunk.originalDataSize * 8000 / waveHeader.bitsPerSample / waveHeader.audioSampleRate;
                 break;
 
             case "AVI ":

test-unit/riff/riffFileTests.ts

@@ -359,7 +359,7 @@ import {Testers} from "../utilities/testers";
             assert.strictEqual(file.properties.codecs.length, 1);
             assert.isOk(file.properties.codecs.find((c) => c instanceof RiffWaveFormatEx));
             assert.isNotOk(file.properties.codecs.find((c) => c instanceof RiffBitmapInfoHeader));
-            assert.approximately(file.properties.durationMilliseconds, 405, 1);
+            assert.approximately(file.properties.durationMilliseconds, 426, 1);
 
             assert.isOk(file.tag);
             assert.instanceOf(file.tag, RiffTags);
@@ -399,7 +399,7 @@ import {Testers} from "../utilities/testers";
             assert.strictEqual(file.properties.codecs.length, 1);
             assert.isOk(file.properties.codecs.find((c) => c instanceof RiffWaveFormatEx));
             assert.isNotOk(file.properties.codecs.find((c) => c instanceof RiffBitmapInfoHeader));
-            assert.approximately(file.properties.durationMilliseconds, 405, 1);
+            assert.approximately(file.properties.durationMilliseconds, 426, 1);
 
             assert.isOk(file.tag);
             assert.instanceOf(file.tag, RiffTags);
@@ -507,7 +507,7 @@ import {Testers} from "../utilities/testers";
         assert.isOk(file.properties.codecs);
         assert.strictEqual(file.properties.codecs.length, 1);
         assert.isOk(file.properties.codecs.find((c) => c instanceof RiffWaveFormatEx));
-        assert.approximately(file.properties.durationMilliseconds, 405, 1);
+        assert.approximately(file.properties.durationMilliseconds, 426, 1);
 
         assert.isOk(file.tag);
         assert.instanceOf(file.tag, RiffTags);