ffmpeg hangs on large HEVC video encoding (image-mp4)

[LALITH0110]

Description

ffmpeg gets stuck at frame=0 when encoding certain large HEVC videos, causing infinite loop and server timeout.

Error

[libx264 @ 0x576011df9500] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x576011df9500] profile High, level 5.1, 4:2:0, 8-bit
frame= 0 fps=0.0 q=0.0 size= 0KiB time=N/A bitrate=N/A speed=N/A
frame= 0 fps=0.0 q=0.0 size= 0KiB time=N/A bitrate=N/A speed=N/A
[repeats forever, never progresses]

Video Info

• Input: HEVC (Main), 2160x3732, 24fps, 22.5s duration
• Output: h264 with preset "slow"
• Bitrate: 32021 kb/s

Issue

subprocess.run() has no timeout - hangs indefinitely when ffmpeg stalls. Server eventually killed by Gunicorn timeout.

Proposed Fix

Add timeout to ffmpeg subprocess:

result = subprocess.run(ffmpeg_cmd, timeout=300)  # 5 min max

And/or change preset from "slow" to "medium" for faster encoding.

Frequency

Rare - large portrait 4K videos from certain phones