Fix float PCM endianness handling in MP4 extraction

rohitjoins · copybara-github · commit cd197994472f · 2026-02-25T06:34:15.000-08:00
This change adds an explicit endianness check (`!isBigEndian`) when parsing the audio sample entry in `BoxParser.java` to prevent mapping big-endian 32-bit float audio to a little-endian encoding, avoiding static noise during playback. Issue: #3063 PiperOrigin-RevId: 875133592
diff --git a/libraries/extractor/src/main/java/androidx/media3/extractor/mp4/BoxParser.java b/libraries/extractor/src/main/java/androidx/media3/extractor/mp4/BoxParser.java
@@ -2139,7 +2139,7 @@ private static void parseAudioSampleEntry(
         } else if (bitsPerSample == 32) {
           pcmEncoding = isBigEndian ? C.ENCODING_PCM_32BIT_BIG_ENDIAN : C.ENCODING_PCM_32BIT;
         }
-      } else if (bitsPerSample == 32) {
+      } else if (!isBigEndian && bitsPerSample == 32) {
         pcmEncoding = C.ENCODING_PCM_FLOAT;
       }
       parent.skipBytes(8); // constBytesPerAudioPacket, constLPCMFramesPerAudioPacket

Original file line number	Diff line number	Diff line change
`@@ -2139,7 +2139,7 @@ private static void parseAudioSampleEntry(`
`2139`	`2139`	`} else if (bitsPerSample == 32) {`
`2140`	`2140`	`pcmEncoding = isBigEndian ? C.ENCODING_PCM_32BIT_BIG_ENDIAN : C.ENCODING_PCM_32BIT;`
`2141`	`2141`	`}`
`2142`		`- } else if (bitsPerSample == 32) {`
	`2142`	`+ } else if (!isBigEndian && bitsPerSample == 32) {`
`2143`	`2143`	`pcmEncoding = C.ENCODING_PCM_FLOAT;`
`2144`	`2144`	`}`
`2145`	`2145`	`parent.skipBytes(8); // constBytesPerAudioPacket, constLPCMFramesPerAudioPacket`