[BUG] Tidal Hi-Res FLAC silently downgrades to AAC 320 — root cause is DASH-MPD manifest not handled by get_downloadable

[andrewle8]

Describe the bug

Tidal now serves HI_RES_LOSSLESS (and in some regions/albums also LOSSLESS) as manifestMimeType: application/dash+xml — a multi-segment DASH-MPD manifest pointing at fragmented MP4 (fMP4) segments containing the FLAC stream. Streamrip 2.2.0 and the current dev branch only parse the older application/vnd.tidal.bts (single-URL BTS-JSON) format. The XML manifest raises JSONDecodeError inside get_downloadable, the except block calls itself recursively at quality n-1, and Tidal's API then server-side downgrades LOSSLESS → HIGH (AAC 320 BTS-JSON), which parses successfully — so the user gets a silent fallback to a .m4a file with no error.

This is the underlying cause of #970, #966, #892, and the long thread in #801. None of those reports identified the DASH transition; they all attribute it to client_id/client_secret rotation. The credentials are not the problem — the manifest format is.

Root cause

streamrip/client/tidal.py (line ~165 on dev and 2.2.0):

async def get_downloadable(self, track_id: str, quality: int):
    ...
    resp = await self._api_request(
        f"tracks/{track_id}/playbackinfopostpaywall", params
    )
    try:
        manifest = json.loads(base64.b64decode(resp["manifest"]).decode("utf-8"))
    except KeyError:
        raise Exception(resp["userMessage"])
    except JSONDecodeError:
        logger.warning(
            f"Failed to get manifest for {track_id}. Retrying with lower quality."
        )
        return await self.get_downloadable(track_id, quality - 1)
    ...
    return TidalDownloadable(
        ...
        url=manifest["urls"][0],
        codec=manifest["codecs"],
        ...
    )

The code assumes resp["manifest"] base64-decodes to JSON. For Hi-Res, it now decodes to:

<?xml version='1.0' encoding='UTF-8'?>
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" ...>
  <Period id="0">
    <AdaptationSet id="0" contentType="audio" mimeType="audio/mp4" ...>
      <Representation id="FLAC_HIRES,96000,24" codecs="flac" bandwidth="2773973" audioSamplingRate="96000">
        <SegmentTemplate timescale="96000"
          initialization="https://sp-ad-fa.audio.tidal.com/mediatracks/.../0.mp4?token=..."
          media="https://sp-ad-fa.audio.tidal.com/mediatracks/.../$Number$.mp4?token=..."
          startNumber="1">
          <SegmentTimeline>
            <S d="380928" r="69"/>
            <S d="128210"/>
          </SegmentTimeline>
        </SegmentTemplate>
      </Representation>
    </AdaptationSet>
  </Period>
</MPD>

The response also carries manifestMimeType: application/dash+xml which the current code never inspects.

Reproduce

# Use an album you know is Hi-Res in the Tidal app:
rip --no-db --quality 3 url "https://tidal.com/album/505811027"

Result: 10 .m4a files at AAC 320, no warning about quality loss beyond the (silent-on-the-surface) "Failed to get manifest. Retrying with lower quality." log line.

Verify with curl that Tidal does have FLAC for the same tracks:

TOKEN=$(grep '^access_token' "$HOME/Library/Application Support/streamrip/config.toml" | sed 's/access_token = "//;s/"$//')
curl -sS "https://api.tidal.com/v1/tracks/505811029/playbackinfopostpaywall?audioquality=HI_RES_LOSSLESS&playbackmode=STREAM&assetpresentation=FULL&countryCode=US" \
  -H "Authorization: Bearer $TOKEN" | python3 -c "
import sys, json, base64
d = json.load(sys.stdin)
print('audioQuality:', d['audioQuality'])
print('manifestMimeType:', d['manifestMimeType'])
print('bitDepth:', d.get('bitDepth'), 'sampleRate:', d.get('sampleRate'))
print(base64.b64decode(d['manifest']).decode()[:300])
"

Expected output: audioQuality: HI_RES_LOSSLESS, manifestMimeType: application/dash+xml, bitDepth: 24, sampleRate: 96000, followed by the MPD XML.

Proposed fix

get_downloadable should dispatch on resp.get("manifestMimeType"):

• application/vnd.tidal.bts → existing JSON path (unchanged)
• application/dash+xml → parse MPD, build a downloader that:
  1. Fetches SegmentTemplate/@initialization (the init segment)
  2. Fetches each numbered media segment (media URL with $Number$ substituted), startNumber through startNumber + sum((S.r or 0) + 1)
  3. Concatenates init + segments into a single fMP4 stream
  4. Optionally remuxes to native FLAC via ffmpeg -i in.mp4 -map 0:a -c:a copy out.flac (lossless, no re-encode)

No DRM is in play for the FLAC AdaptationSet (no <ContentProtection> element), so this is a plain HTTP segmented download. fMP4-FLAC is a standard container; ffmpeg copies the FLAC frames out without modification.

A working reference implementation (~250 LOC of stdlib + ffmpeg + mutagen) — happy to attach inline or open a PR. The MPD parser is just xml.etree.ElementTree against the namespace urn:mpeg:dash:schema:mpd:2011, and segment downloads are plain urllib.request (no special headers needed beyond the signed URL).

Workaround

Until this lands, use the standalone script above or any DASH-aware downloader (e.g. yt-dlp with --allow-unplayable-formats, though that re-muxes differently).

Environment

• streamrip 2.2.0 (from nathom/streamrip@v2.2.0 via pipx)
• dev branch HEAD as of 2026-05-20: same broken code path
• Tested on macOS (Apple Silicon), but the bug is in protocol handling — OS-independent
• Tidal HiFi Plus account, US region, account confirmed to deliver FLAC to the Tidal app for the same albums