Post-processing for subtitle files still doesn't work.

[Riglav]

Checklist

• I am able to reproduce the bug with the latest version given here: CLICK THIS LINK.
• I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• I have read the FAQ and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.
• I have read and understood the AI policy. The content of this bug report is not generated by AI.

Affected version

0.28.3

Steps to reproduce the bug

1. Download any subtitles (it doesn't matter if they are automatically generated or not);
2. Wait for post-processing;
3. Observe.

Expected behavior

No response

Actual behavior

No response

Screenshots/Screen recordings

No response

Logs

Exception

• User Action: download post-processing
• Request: https://www.youtube.com/watch?v=8NGNYGnKjQ8 [ {type=subtitles format=Timed Text Markup Language language=en autoGenerated=true} ]
• Content Country: US
• Content Language: en-
• App Language: ru
• Service: YouTube
• Timestamp: 2026-03-09T18:50:39.845+03:00
• Package: org.schabi.newpipe
• Service: YouTube
• Version: 0.28.4
• OS: Linux Android 5.1 - 22

Crash log

java.io.IOException: TTML to SRT conversion failed
	at us.shandian.giga.postprocessing.M4aNoDash.process(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:1753)
	at us.shandian.giga.postprocessing.Postprocessing.run(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:160)
	at us.shandian.giga.get.DownloadMission$$ExternalSyntheticLambda0.run(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:36)
	at java.lang.Thread.run(Thread.java:831)
Caused by: java.lang.IllegalArgumentException: Bad position (limit 991): -66
	at java.nio.Buffer.positionImpl(Buffer.java:351)
	at java.nio.Buffer.position(Buffer.java:345)
	at java.nio.charset.CharsetDecoderICU.setPosition(CharsetDecoderICU.java:205)
	at java.nio.charset.CharsetDecoderICU.decodeLoop(CharsetDecoderICU.java:154)
	at java.nio.charset.CharsetDecoder.decode(CharsetDecoder.java:306)
	at org.jsoup.internal.SimpleStreamReader.read(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:26)
	at org.jsoup.parser.CharacterReader.bufferUp(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:49)
	at org.jsoup.parser.CharacterReader.current(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:1)
	at org.jsoup.parser.TokeniserState$1.read(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:1)
	at org.jsoup.parser.TreeBuilder.runParser(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:53)
	at org.jsoup.helper.DataUtil.parseInputStream(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:31)
	at org.schabi.newpipe.streams.SrtFromTtmlWriter.build(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:47)
	at us.shandian.giga.postprocessing.M4aNoDash.process(r8-map-id-ce0307bac2c3f16e8dc2f832773b0599f307ee51c82b5550b73911d8a6d3ce37:1736)
	... 3 more

---

---

java.lang.RuntimeException: post-processing algorithm returned 8
at us.shandian.giga.postprocessing.Postprocessing.run(Postprocessing.java:207)
at us.shandian.giga.get.DownloadMission.doPostprocessing(DownloadMission.java:701)
at us.shandian.giga.get.DownloadMission.$r8$lambda$IA0_L2vJSLZLqg0BQARF8wvRshk(DownloadMission.java:0)
at us.shandian.giga.get.DownloadMission$$ExternalSyntheticLambda0.run(R8$$SyntheticClass:0)
at java.lang.Thread.run(Thread.java:831)

Affected Android/Custom ROM version

Android 5

Affected device model

Huawei CUN-U29.A.RX.VO1

Additional information

No response

[TobiGr]

Please add more info. Which subtitles did you download, from where? Stream URL and language snf format are needed.

[Riglav]

This thing?

No matter which captions I try to download (from YT, I don't use another platforms), there's always a post-processing error.

[TobiGr]

please copy the full error report and post it here. there is a button for marksown / github export

[Riglav]

Like this?

Exception

• User Action: download post-processing
• Request: https://www.youtube.com/watch?v=cMtJsoVuoes [ {type=subtitles format=Timed Text Markup Language language=en autoGenerated=true} ]
• Content Country: US
• Content Language: en-
• App Language: en
• Service: YouTube
• Timestamp: 2026-02-08T19:04:02.91+03:00
• Package: org.schabi.newpipe
• Service: YouTube
• Version: 0.28.3
• OS: Linux Android 5.1 - 22

Crash log

java.lang.RuntimeException: post-processing algorithm returned 8
	at us.shandian.giga.postprocessing.Postprocessing.run(Postprocessing.java:207)
	at us.shandian.giga.get.DownloadMission.doPostprocessing(DownloadMission.java:701)
	at us.shandian.giga.get.DownloadMission.$r8$lambda$IA0_L2vJSLZLqg0BQARF8wvRshk(DownloadMission.java:0)
	at us.shandian.giga.get.DownloadMission$$ExternalSyntheticLambda0.run(R8$$SyntheticClass:0)
	at java.lang.Thread.run(Thread.java:831)

---

Does downloading video or audio work for you?

[Riglav]

Downloading for both video and audio is working. Post-processing for downloaded captions is not.

NewPipe/app/src/main/java/us/shandian/giga/postprocessing/TtmlConverter.java

Lines 27 to 35 in dab8e05

	if (format == null || format.equals("ttml")) {
	SrtFromTtmlWriter writer = new SrtFromTtmlWriter(out, ignoreEmptyFrames);
	try {
	writer.build(sources[0]);
	} catch (Exception err) {
	Log.e(TAG, "subtitle parse failed", err);
	return err instanceof IOException ? 1 : 8;
	}

Notice SrtFromTtmlWriter is part of org/schabi/newpipe package so it is probably not bug in the dependecy

Reported exception is just an exception dumbly unwrapped to int. What we can surely say that actual exception IS NOT IOEXCEPTION

@Riglav can you access logcat logs of your device?

[Riglav]

No, because root is required, and rooting the device actually do nothing.

No, because root is required, and rooting the device actually do nothing.

Root isn't required. It is possible to do it with adb and android developer settings which doesn't require root but requires external device. IIRC some people even manage to connect adb from termux (app on android) to the device itself... I don't propose you last method just mention possibility