From e0d3f22f16eb53734068cba3daeff99c940251e5 Mon Sep 17 00:00:00 2001
From: aliveoutside <53598473+aliveoutside@users.noreply.github.com>
Date: Fri, 16 Feb 2024 06:32:53 +0300
Subject: [PATCH] improve demuxer performance

use buffered io for input and output streams
reuse single bytebuffer instead of creating it for every packet
---
 .../ru/vtosters/lite/music/converter/ts/MpegDemuxer.java  | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/ru/vtosters/lite/music/converter/ts/MpegDemuxer.java b/app/src/main/java/ru/vtosters/lite/music/converter/ts/MpegDemuxer.java
index 7746878be..f7302df06 100644
--- a/app/src/main/java/ru/vtosters/lite/music/converter/ts/MpegDemuxer.java
+++ b/app/src/main/java/ru/vtosters/lite/music/converter/ts/MpegDemuxer.java
@@ -4,6 +4,8 @@ import android.util.Log;
 
 import com.vk.dto.music.MusicTrack;
 
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -17,10 +19,11 @@ public class MpegDemuxer {
         int desiredPid = 256;
 
         var buffer = new byte[packetSize];
+        var packet = ByteBuffer.wrap(buffer).order(ByteOrder.BIG_ENDIAN);
 
-        try (var fis = new FileInputStream(in); var fos = new FileOutputStream(out)) {
+        try (var fis = new BufferedInputStream(new FileInputStream(in)); var fos = new BufferedOutputStream(new FileOutputStream(out))) {
             while (fis.read(buffer) != -1) {
-                var packet = ByteBuffer.wrap(buffer).order(ByteOrder.BIG_ENDIAN);
+                packet.clear();
 
                 int firstByte = packet.get() & 0xFF;
                 int secondByte = packet.get() & 0xFF;
@@ -65,7 +68,6 @@ public class MpegDemuxer {
                     }
 
                     fos.write(packet.array(), packet.position(), packetSize - packet.position());
-                    packet.clear();
                 }
             }
         }