latest - sabr-shaka-example fails

[WardPearce]

Steps to reproduce

Load video "N0I4-UHI5uU" (occurs on other videos, but not all)

Buffers until error is produced

Failure Logs

{
    "severity": 2,
    "category": 1,
    "code": 1007,
    "data": [
        {
            "severity": 2,
            "category": 1,
            "code": 1002,
            "data": [
                "Server streaming error",
                {
                    "info": {
                        "format": {
                            "itag": 140,
                            "lastModified": "1762919124974192",
                            "mimeType": "audio/mp4; codecs=\"mp4a.40.2\"",
                            "audioQuality": "AUDIO_QUALITY_MEDIUM",
                            "bitrate": 130977,
                            "averageBitrate": 129499,
                            "quality": "tiny",
                            "approxDurationMs": 365853,
                            "contentLength": 5922203,
                            "isDrc": false,
                            "isAutoDubbed": false,
                            "isDescriptive": false,
                            "isDubbed": false,
                            "language": "en",
                            "isOriginal": true,
                            "isSecondary": false
                        },
                        "isUMP": true,
                        "isSABR": true,
                        "isInit": true,
                        "byteRange": {
                            "start": 723,
                            "end": 1198
                        },
                        "timestamp": 1762958284891,
                        "error": {
                            "sabrError": {
                                "type": "sabr.malformed_config",
                                "code": 2
                            }
                        }
                    }
                }
            ],
            "handled": false,
            "message": "Shaka Error 1002",
            "stack": "Error: Shaka Error 1002\n    at new U (http://localhost:5173/node_modules/.vite/deps/chunk-X26JZVI5.js?v=cfb615ae:1366:19)\n    at createRecoverableError (http://localhost:5173/src/helpers.ts:32:10)\n    at checkResultIntegrity (http://localhost:5173/src/ShakaPlayerAdapter.ts?t=1762958278994:132:15)\n    at ShakaPlayerAdapter.handleUmpResponse (http://localhost:5173/src/ShakaPlayerAdapter.ts?t=1762958278994:211:23)"
        }
    ],
    "handled": false,
    "message": "Shaka Error 1007",
    "stack": "Error: Shaka Error 1007\n    at new U (http://localhost:5173/node_modules/.vite/deps/chunk-X26JZVI5.js?v=cfb615ae:1366:19)\n    at http://localhost:5173/node_modules/.vite/deps/chunk-X26JZVI5.js?v=cfb615ae:4606:19\n    at Vg (http://localhost:5173/node_modules/.vite/deps/chunk-X26JZVI5.js?v=cfb615ae:4343:21)\n    at http://localhost:5173/node_modules/.vite/deps/chunk-X26JZVI5.js?v=cfb615ae:4324:25"
}

Expected behavior

N/A

Current behavior

N/A

Version

Default

Anything else?

No response

Checklist

• I am running the latest version.
• I checked the documentation and found no answer.
• I have searched the existing issues and made sure this is not a duplicate.
• I have provided sufficient information.

[unixfox]

This is due to duplicated itags with different xtags. The fix was handled in LuanRT/YouTube.js#1092 but there hasn't been any fix in googlevideo lib for SABR yet.

My temporary fix is to filter out itags with "xtags":

<       sabrAdapter.setServerAbrFormats(videoInfo.streaming_data.adaptive_formats.map(buildSabrFormat));
---
>       sabrAdapter.setServerAbrFormats(videoInfo.streaming_data.adaptive_formats.map(buildSabrFormat).filter(format => !format.xtags));

I understood a bit more the original issue thanks to some AI, you can find the detailed summary:

Detailed issue by AI

Issue Summary

When loading certain videos (e.g., N0I4-UHI5uU), SABR streaming fails with error sabr.malformed_config. The issue appears to be related to audio streams having duplicate itag entries with xtags and isDrc fields (Dynamic Range Control variants).

Error Details

{
    "severity": 2,
    "category": 1,
    "code": 1007,
    "data": [
        {
            "severity": 2,
            "category": 1,
            "code": 1002,
            "data": [
                "Server streaming error",
                {
                    "info": {
                        "format": {
                            "itag": 140,
                            "mimeType": "audio/mp4; codecs=\"mp4a.40.2\"",
                            "audioQuality": "AUDIO_QUALITY_MEDIUM"
                        },
                        "isUMP": true,
                        "isSABR": true,
                        "isInit": true,
                        "byteRange": {
                            "start": 723,
                            "end": 1198
                        },
                        "error": {
                            "sabrError": {
                                "type": "sabr.malformed_config",
                                "code": 2
                            }
                        }
                    }
                }
            ]
        }
    ]
}

Shaka Player Error 1002: Server streaming error
Shaka Player Error 1007: Load interrupted

Root Cause Analysis

Duplicate itag Entries

Videos that exhibit this behavior contain duplicate itag entries in the adaptiveFormats array. For example, itag 140 appears twice:

// First entry (standard)
{
    "itag": 140,
    "mimeType": "audio/mp4; codecs=\"mp4a.40.2\"",
    "loudnessDb": 3.14,
    "trackAbsoluteLoudnessLkfs": -10.86,
    "isDrc": false
}

// Second entry (DRC variant)
{
    "itag": 140,
    "mimeType": "audio/mp4; codecs=\"mp4a.40.2\"",
    "xtags": "CggKA2RyYxIBMQ",
    "loudnessDb": 0,
    "isDrc": true,
    "trackAbsoluteLoudnessLkfs": -14
}

The same pattern occurs for itags:

• 140 (audio/mp4)
• 249 (audio/webm opus)
• 250 (audio/webm opus)
• 251 (audio/webm opus)

Affected vs Unaffected Video Comparison

Property	Working Video	Failing Video
Video ID	-	N0I4-UHI5uU
Duration	~283 sec	~1328 sec
Max Resolution	1080p	2160p (4K)
Duplicate itags	❌ No	✅ Yes
xtags field	❌ Absent	✅ Present
isDrc field	❌ Absent	✅ Present
URL Format	signatureCipher	Direct url

Format Differences

Working Video (good.json)

• Video formats: itag 18 uses signatureCipher (encrypted URL)
• Audio formats: Single entry per itag (4 total audio tracks)
• No DRC variants

Failing Video (bad.json)

• Video formats: itag 18 uses direct url field
• Audio formats: Duplicate entries per itag with DRC variants (8 total audio tracks)
• DRC variants present: xtags: "CggKA2RyYxIBMQ", isDrc: true, loudnessDb: 0

Hypothesis

The googlevideo library's SABR parser may:

1. Not handle duplicate itag entries correctly when processing the streaming data
2. Fail to parse or ignore the xtags field
3. Not differentiate between standard and DRC audio streams
4. Attempt to use wrong audio stream causing malformed config error

When SABR (Server Adapative Bitrate Streaming) is enabled with serverAbrStreamingUrl, the library needs to select appropriate formats. The presence of duplicate itags likely causes:

• Ambiguity in format selection
• Incorrect parsing of the streaming configuration
• Failure to properly initialize UMP (Universal Media Protocol) streams

Steps to Reproduce

1. Load video with ID N0I4-UHI5uU (or any video with duplicate audio itags and xtags field)
2. Enable SABR streaming
3. Attempt to play video using Shaka Player
4. Player buffers then throws sabr.malformed_config error

Expected Behavior

The library should:

1. Handle duplicate itag entries gracefully
2. Parse xtags field correctly or ignore it
3. Select appropriate audio stream (prefer standard over DRC, or allow selection)
4. Successfully initialize SABR streaming without errors

Workaround

Until this is fixed, potential workarounds:

1. Filter out DRC variants before passing to SABR:

   const filteredFormats = adaptiveFormats.filter(f => !f.isDrc);

2. Filter by xtags presence:

   const filteredFormats = adaptiveFormats.filter(f => !f.xtags);

3. Use non-SABR streaming as fallback