I am unable to use opencv cap.read() on .avi files since it crashes there. There seems to be some problem with fourcc since it returns 0.0 and cap.IsOpened returns true. The fps, width, height are returned correctly as well. I can play the .avi files without a problem using IINA and I cannot convert to any other video file format.
import cv2
video_path = '/Users/aravind/Downloads/test.avi'
cap = cv2.VideoCapture(video_path)
print(cap.get(cv2.CAP_PROP_FOURCC)
print("FPS:", cap.get(cv2.CAP_PROP_FPS)
print("Frame count:", cap.get(cv2.CAP_PROP_FRAME_COUNT))
print("Width:", cap.get(cv2.CAP_PROP_FRAME_WIDTH))
print("Height:", cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
while cap.isOpened():
print("Working here")
ret, frame = cap.read() # crashes here
Running
ffprobe -v quiet -print_format json -show_streams /Users/aravind/Downloads/test.avi gives:
{
"streams": [
{
"index": 0,
"codec_name": "rawvideo",
"codec_long_name": "raw video",
"codec_type": "video",
"codec_tag_string": "[0][0][0][0]",
"codec_tag": "0x0000",
"width": 192,
"height": 192,
"coded_width": 192,
"coded_height": 192,
"has_b_frames": 0,
"pix_fmt": "bgr24",
"level": -99,
"r_frame_rate": "30/1",
"avg_frame_rate": "30/1",
"time_base": "1/30",
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 60,
"duration": "2.000000",
"bit_rate": "26991946",
"nb_frames": "60",
"extradata_size": 9,
"disposition": {
"default": 0,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0,
"non_diegetic": 0,
"captions": 0,
"descriptions": 0,
"metadata": 0,
"dependent": 0,
"still_image": 0,
"multilayer": 0
}
}
]
}
Running
ffmpeg -i /Users/aravind/Downloads/test.avi -vframes 1 /tmp/test_frame.png 2>&1
gives the below print and the expected first frame in /tmp/test_frame.png:
ffmpeg version 8.1 Copyright (c) 2000-2026 the FFmpeg developers
built with Apple clang version 21.0.0 (clang-2100.0.123.102)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/8.1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gpl --enable-libsvtav1 --enable-libopus --enable-libx264 --enable-libmp3lame --enable-libdav1d --enable-libvmaf --enable-libvpx --enable-libx265 --enable-openssl --enable-videotoolbox --enable-audiotoolbox --enable-neon
libavutil 60. 26.100 / 60. 26.100
libavcodec 62. 28.100 / 62. 28.100
libavformat 62. 12.100 / 62. 12.100
libavdevice 62. 3.100 / 62. 3.100
libavfilter 11. 14.100 / 11. 14.100
libswscale 9. 5.100 / 9. 5.100
libswresample 6. 3.100 / 6. 3.100
Input #0, avi, from '/Users/aravind/Downloads/test.avi':
Duration: 00:00:02.00, start: 0.000000, bitrate: 26813 kb/s
Stream #0:0: Video: rawvideo, bgr24, 192x192, 26991 kb/s, 30 fps, 30 tbr, 30 tbn
File '/tmp/test_frame.png' already exists. Overwrite? [y/N] y
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> png (native))
Press [q] to stop, [?] for help
Output #0, image2, to '/tmp/test_frame.png':
Metadata:
encoder : Lavf62.12.100
Stream #0:0: Video: png, rgb24(pc, gbr/unknown/unknown, progressive), 192x192, q=2-31, 200 kb/s, 30 fps, 30 tbn
Metadata:
encoder : Lavc62.28.100 png
[image2 @ 0xbe7018280] The specified filename '/tmp/test_frame.png' does not contain an image sequence pattern or a pattern is invalid.
[image2 @ 0xbe7018280] Use a pattern such as %03d for an image sequence or use the -update option (with -frames:v 1 if needed) to write a single image.
[out#0/image2 @ 0xbe6c54180] video:2KiB audio:0KiB subtitle:0KiB other streams:0KiB global headers:0KiB muxing overhead: unknown
frame= 1 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.03 bitrate=N/A speed=7.15x elapsed=0:00:00.00
