Verify

Overview

verify inspects an existing media file with ffprobe and prints its container and per-stream properties. Use it to confirm a generated file (or any file) has the codec, resolution, fps, and duration you expect — a natural “generate then check” step for CI or agents.

encfixture verify test.mp4

Output

$ encfixture verify test.mp4
File:     test.mp4
Format:   mov,mp4,m4a,3gp,3g2,mj2
Duration: 2.000000s
Size:     28934 bytes
Stream 0: video  h264  1920x1080  30fps  yuv420p
Stream 1: audio  aac  48000Hz  2ch

Assertions (--expect)

Pass one or more --expect key=value assertions to turn verify into a one-shot pass/fail gate. Each expectation is checked against the probed properties; the command exits non-zero (error code verify_failed) if any fail.

encfixture verify test.mp4 --expect codec=h264 --expect width=1920 --expect duration=5

$ encfixture verify test.mp4 --expect codec=hevc --expect duration=5
File:     test.mp4
...
FAIL  codec: expected hevc, actual h264
PASS  duration = 5.016000
encfixture: verification failed: 1 of 2 expectations failed

Key	Checks
codec, width, height, fps, pixFmt	First video stream
audioCodec, sampleRate, channels	First audio stream
duration	Container duration

Keys are case-insensitive, and kebab-case aliases (pix-fmt, audio-codec, sample-rate) are also accepted. Numeric keys take an optional tolerance suffix written 5+-0.2 (or 5±0.2). By default duration allows ±0.1s (container rounding) and fps ±0.001 (so fps=29.97 matches ffprobe’s 29.970); other keys compare exactly. A missing stream fails the check with (no video stream) / (no audio stream) as the actual value.

JSON output

Add --json for a machine-readable result.

$ encfixture verify --json test.mp4
{"status":"ok","file":"test.mp4","format":{"formatName":"mov,mp4,...","duration":"2.000000","size":"28934","bitRate":"115736"},"streams":[{"index":0,"type":"video","codec":"h264","width":1920,"height":1080,"fps":"30","pixFmt":"yuv420p"},{"index":1,"type":"audio","codec":"aac","sampleRate":"48000","channels":2}]}

With --expect, the result adds a checks array and status becomes ok or failed:

$ encfixture verify --json test.mp4 --expect codec=hevc
{"status":"failed","file":"test.mp4","format":{...},"streams":[...],"checks":[{"field":"codec","expected":"hevc","actual":"h264","pass":false}]}

Fields

Field	Description
format.formatName	Container format(s) reported by ffprobe
format.duration	Duration in seconds
format.size	File size in bytes
format.bitRate	Overall bit rate
streams[].type	video or audio
streams[].codec	Codec name (e.g. h264, aac)
streams[].width / height	Video resolution
streams[].fps	Frame rate (30, 29.970, …)
streams[].pixFmt	Pixel format
streams[].sampleRate / channels	Audio sample rate and channel count

Requirements

verify requires ffprobe, which ships with ffmpeg. A missing file or unreadable input surfaces ffprobe’s error message and exits non-zero.