fix(ios): auto-fallback from PCM to MP3 for ElevenLabs TTS by leepokai · Pull Request #30885 · openclaw/openclaw

leepokai · 2026-03-01T18:44:17Z

Summary

Keep pcm_44100 as the default TTS output format (better quality/lower latency for Pro users)
When the ElevenLabs API rejects PCM with HTTP 403 (subscription_required), automatically fall back to mp3_44100_128 and set pcmFormatUnavailable to skip PCM for all subsequent requests in the session
The flag resets on reloadConfig() (reconnect/new session) so it re-probes the API
Standardize MP3 fallback format from mp3_44100 to mp3_44100_128 for consistent bitrate

Root cause

pcm_44100 output format requires an ElevenLabs Pro tier subscription. Users on free or starter plans receive a silent HTTP 403 error, causing TTS to fail with no audio output. The existing PCM-to-MP3 retry path fired on every segment without remembering the failure, wasting an API call each time.

Test plan

ElevenLabs Pro user: default PCM format works, no fallback triggered
ElevenLabs free/starter user: first TTS segment retries with MP3, all subsequent segments use MP3 directly (no double API calls)
After gateway reconnect, the format preference resets and re-probes PCM
Explicit outputFormat in talk config overrides the default (both PCM and MP3)

🤖 Generated with Claude Code

The default output format pcm_44100 requires an ElevenLabs Pro tier subscription. Users on free or starter plans get a silent 403 failure and hear no audio. Instead of hardcoding mp3, keep pcm_44100 as the default (better quality for Pro users) but remember the failure: when a PCM request is rejected, set pcmFormatUnavailable and use mp3_44100_128 for all subsequent requests in the session. The flag resets on config reload so it re-probes after reconnection. Also standardize the MP3 fallback format from mp3_44100 to mp3_44100_128 for consistent bitrate. Co-Authored-By: Claude Opus 4.6 <[email protected]>

chatgpt-codex-connector

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: fbc26ef9f3

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

Open a pull request for review
Mark a draft as ready
Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

chatgpt-codex-connector · 2026-03-01T18:47:19Z

apps/ios/Sources/Voice/TalkModeManager.swift

            self.gatewayTalkDefaultModelId = nil
            self.gatewayTalkApiKeyConfigured = false
            self.gatewayTalkConfigLoaded = false
+            self.pcmFormatUnavailable = false


Reset PCM fallback state on successful config reloads

pcmFormatUnavailable is only cleared in the catch branch of reloadConfig(), so a normal reconnect/config refresh leaves the flag stuck once it has been set. After a single PCM failure, subsequent sessions in the same app process will keep defaulting to MP3 instead of re-probing PCM, which contradicts the intended reconnect behavior and causes avoidable quality/latency degradation for users who can use PCM.

Useful? React with 👍 / 👎.

chatgpt-codex-connector · 2026-03-01T18:47:19Z

apps/ios/Sources/Voice/TalkModeManager.swift

            var playback = await self.pcmPlayer.play(stream: stream, sampleRate: sampleRate)
            if !playback.finished, playback.interruptedAt == nil {
                self.logger.warning("pcm playback failed; retrying mp3")
+                self.pcmFormatUnavailable = true


Invalidate incremental context after marking PCM unavailable

When incremental playback hits a PCM failure, this sets pcmFormatUnavailable but does not refresh the cached IncrementalSpeechContext; updateIncrementalContextIfNeeded() reuses that context while the directive is unchanged, so context.outputFormat can remain PCM for later segments. In cases where prefetched MP3 audio is unavailable, speakIncrementalSegment will still issue a new PCM synthesis request and then retry MP3, so the new “skip PCM after first failure” optimization is not consistently applied in incremental mode.

Useful? React with 👍 / 👎.

greptile-apps · 2026-03-01T18:50:15Z

Greptile Summary

This PR implements a session-level fallback from PCM to MP3 for ElevenLabs TTS when the API rejects the PCM format (typically due to subscription tier limitations). The implementation correctly adds a pcmFormatUnavailable flag and uses it via effectiveDefaultOutputFormat to avoid repeated PCM attempts after initial failure. MP3 format is also standardized to mp3_44100_128 for consistent bitrate.

Critical issue found: The flag is only reset in the catch block of reloadConfig() (line 2006), meaning it will NOT reset on successful reconnection. This breaks the intended re-probe behavior described in the PR description. The flag should be reset at the start of reloadConfig() to re-probe PCM on every config reload.

Confidence Score: 2/5

Critical logic bug prevents the re-probe behavior from working as designed
The flag reset placement in the error path instead of success path will prevent PCM format from being re-tried after successful reconnection, breaking core functionality described in the PR. The rest of the implementation is sound.
apps/ios/Sources/Voice/TalkModeManager.swift - flag reset logic needs correction

_{Last reviewed commit: fbc26ef}

greptile-apps

_{1 file reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

greptile-apps · 2026-03-01T18:50:18Z

apps/ios/Sources/Voice/TalkModeManager.swift

            self.gatewayTalkDefaultModelId = nil
            self.gatewayTalkApiKeyConfigured = false
            self.gatewayTalkConfigLoaded = false
+            self.pcmFormatUnavailable = false


The flag is only reset in the catch block when config loading fails. It won't reset on successful reconnect, breaking the re-probe behavior described in the PR. Move this to the beginning of reloadConfig() (before line 1935) so it resets on every config reload.

Suggested change

self.pcmFormatUnavailable = false

guard let gateway else { return }

self.pcmFormatUnavailable = false

do {

Prompt To Fix With AI

This is a comment left during a code review. Path: apps/ios/Sources/Voice/TalkModeManager.swift Line: 2006 Comment: The flag is only reset in the catch block when config loading fails. It won't reset on successful reconnect, breaking the re-probe behavior described in the PR. Move this to the beginning of `reloadConfig()` (before line 1935) so it resets on every config reload. ```suggestion guard let gateway else { return } self.pcmFormatUnavailable = false do { ``` How can I resolve this? If you propose a fix, please make it concise.

…probe

@mbelinky

Merged via /review-pr -> /prepare-pr -> /merge-pr. Prepared head SHA: f77e3d7 Co-authored-by: mbelinky <[email protected]> Co-authored-by: mbelinky <[email protected]> Reviewed-by: @mbelinky

mbelinky · 2026-03-03T16:53:19Z

Closing as superseded by merged PR #33032 (merge commit bf70610), which lands this PCM->MP3 fallback behavior (with additional guardrails from stack review). Thanks @leepokai for the original implementation.

@mbelinky

…law#33032) Merged via /review-pr -> /prepare-pr -> /merge-pr. Prepared head SHA: f77e3d7 Co-authored-by: mbelinky <[email protected]> Co-authored-by: mbelinky <[email protected]> Reviewed-by: @mbelinky

openclaw-barnacle bot added app: ios App: ios size: XS labels Mar 1, 2026

chatgpt-codex-connector bot reviewed Mar 1, 2026

View reviewed changes

greptile-apps bot reviewed Mar 1, 2026

View reviewed changes

fix(ios): reset pcmFormatUnavailable at start of reloadConfig for re-…

31ecbbb

…probe

leepokai mentioned this pull request Mar 2, 2026

macOS CI job runs full TS test suite for iOS-only changes, causing timeout #31542

Open

mbelinky mentioned this pull request Mar 3, 2026

iOS Security Stack 4/5: TTS PCM->MP3 Fallback (#30885) #33032

Merged

github-actions bot mentioned this pull request Mar 3, 2026

📡 Upstream Digest — 2026-03-03 16:37 UTC curtismercier/openclaw-mods#173

Open

mbelinky closed this Mar 3, 2026

MillionthOdin16 added a commit to MillionthOdin16/openclaw that referenced this pull request Mar 3, 2026

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

fix(ios): auto-fallback from PCM to MP3 for ElevenLabs TTS#30885

fix(ios): auto-fallback from PCM to MP3 for ElevenLabs TTS#30885
leepokai wants to merge 2 commits intoopenclaw:mainfrom
leepokai:fix/ios-tts-default-mp3

leepokai commented Mar 1, 2026 •

edited

Loading

Uh oh!

chatgpt-codex-connector bot left a comment

Uh oh!

chatgpt-codex-connector bot Mar 1, 2026

Uh oh!

chatgpt-codex-connector bot Mar 1, 2026

Uh oh!

greptile-apps bot commented Mar 1, 2026

Uh oh!

greptile-apps bot left a comment

Uh oh!

greptile-apps bot Mar 1, 2026

Uh oh!

mbelinky commented Mar 3, 2026

Uh oh!

Uh oh!

Conversation

leepokai commented Mar 1, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Root cause

Test plan

Uh oh!

chatgpt-codex-connector bot left a comment

Choose a reason for hiding this comment

💡 Codex Review

Uh oh!

chatgpt-codex-connector bot Mar 1, 2026

Choose a reason for hiding this comment

Uh oh!

chatgpt-codex-connector bot Mar 1, 2026

Choose a reason for hiding this comment

Uh oh!

greptile-apps bot commented Mar 1, 2026

Greptile Summary

Confidence Score: 2/5

Uh oh!

greptile-apps bot left a comment

Choose a reason for hiding this comment

Uh oh!

greptile-apps bot Mar 1, 2026

Choose a reason for hiding this comment

Uh oh!

mbelinky commented Mar 3, 2026

Uh oh!

leepokai commented Mar 1, 2026 •

edited

Loading