What causes "Invalid rendition field." in ytdl-org/youtube-dl?

Update youtube-dl / switch to yt-dlp — this is almost always an out-of-date extractor versus a changed mediagen response.

ytdl-org/youtube-dl · error · ExtractorError

Invalid rendition field.

Error message

Invalid rendition field.

What it means

Raised inside MTV's rendition loop when building the format dict raises KeyError or TypeError — i.e. a rendition element is missing required attributes ('type', 'width', 'height') or its values are malformed. Unlike the geo/availability errors this one is NOT expected=True, so it propagates as an unexpected extraction failure.

Source

Thrown at youtube_dl/extractor/mtv.py:108

                    _, _, ext = rendition.attrib['type'].partition('/')
                    rtmp_video_url = rendition.find('./src').text
                    if 'error_not_available.swf' in rtmp_video_url:
                        raise ExtractorError(
                            '%s said: video is not available' % self.IE_NAME,
                            expected=True)
                    if rtmp_video_url.endswith('siteunavail.png'):
                        continue
                    formats.extend([{
                        'ext': 'flv' if rtmp_video_url.startswith('rtmp') else ext,
                        'url': rtmp_video_url,
                        'format_id': '-'.join(filter(None, [
                            'rtmp' if rtmp_video_url.startswith('rtmp') else None,
                            rendition.get('bitrate')])),
                        'width': int(rendition.get('width')),
                        'height': int(rendition.get('height')),
                    }])
                except (KeyError, TypeError):
                    raise ExtractorError('Invalid rendition field.')
        if formats:
            self._sort_formats(formats)
        return formats

    def _extract_subtitles(self, mdoc, mtvn_id):
        subtitles = {}
        for transcript in mdoc.findall('.//transcript'):
            if transcript.get('kind') != 'captions':
                continue
            lang = transcript.get('srclang')
            for typographic in transcript.findall('./typographic'):
                sub_src = typographic.get('src')
                if not sub_src:
                    continue
                ext = typographic.get('format')
                if ext == 'cea-608':
                    ext = 'scc'
                subtitles.setdefault(lang, []).append({

View on GitHub (pinned to 956b8c5855)

Solutions

Update youtube-dl / switch to yt-dlp — this is almost always an out-of-date extractor versus a changed mediagen response.
If it persists on the latest version, report the URL to the tracker so the rendition parsing can be fixed.
Retry once to rule out a truncated/garbage XML response from the CDN.

Example fix

pip install -U youtube-dl   # or: pip install -U yt-dlp

Defensive patterns

Strategy: try-catch

Try / catch

except ExtractorError as e:
    if 'Invalid rendition field' in str(e):
        report_upstream(url)  # schema change — extractor needs a patch
    else:
        raise

Prevention

Pin a recently updated youtube-dl/yt-dlp — this error means the binary's parsing is stale.
Retry once to rule out truncated CDN XML before assuming schema drift.
Monitor extraction success rates per site to catch schema changes early.

When it happens

Trigger: A mediagen XML <rendition> lacking the 'type' key (KeyError on rendition.attrib['type']) or with non-numeric width/height (TypeError in int(...)), caught and re-raised as this generic message.

Common situations: MTV changing the mediagen schema (new rendition attributes, missing width/height on audio-only renditions); an extractor version lagging behind the site; occasionally transient CDN XML truncation.

Related errors

AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14). Data as JSON: /api/errors/eb314250b233d13e. Report an issue: GitHub.