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→Python
win.close()
win.close()
core.quit()
core.quit()
</syntaxhighlight>
Example demonstrating if video and audio encoding are correct:
<syntaxhighlight lang="python" line>
import subprocess
import json
file_path = "C_dyad1_video2_241123.mp4"
def check_video_file(file_path):
try:
# Run ffprobe to get file metadata in JSON format
result = subprocess.run(
[
"ffprobe",
"-v", "error",
"-show_streams",
"-show_format",
"-print_format", "json",
file_path
],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True
)
metadata = json.loads(result.stdout)
except Exception as e:
print(f"Error running ffprobe: {e}")
return
# Check for video stream
video_stream = next((stream for stream in metadata['streams'] if stream['codec_type'] == 'video'), None)
if video_stream:
# Check video codec
video_codec = video_stream.get('codec_name')
if video_codec == 'h264':
print("Video codec: H.264")
else:
print(f"ERROR: Video codec is NOT H.264 (Found: {video_codec})")
# Extract and report frame rate
if 'r_frame_rate' in video_stream:
raw_frame_rate = video_stream['r_frame_rate']
calculated_frame_rate = eval(raw_frame_rate) # Convert string like "30/1" to float
print(f"Frame rate: {calculated_frame_rate:.2f} FPS (raw: {raw_frame_rate})")
else:
print("ERROR: Could not determine raw frame rate from metadata.")
# Check for constant frame rate
if video_stream.get('avg_frame_rate'):
avg_frame_rate = eval(video_stream['avg_frame_rate'])
if abs(avg_frame_rate - calculated_frame_rate) < 0.01:
print("Frame rate: Constant")
else:
print(f"ERROR: Frame rate is NOT constant (avg_frame_rate: {avg_frame_rate:.2f} FPS)")
else:
print("ERROR: Could not determine average frame rate consistency.")
# Check for frame drops
try:
frame_info_result = subprocess.run(
[
"ffprobe",
"-v", "error",
"-select_streams", "v:0",
"-show_entries", "frame=pkt_pts_time",
"-of", "csv=p=0",
file_path
],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True
)
# Filter out empty or invalid lines
frame_times = [
float(line.strip()) for line in frame_info_result.stdout.splitlines()
if line.strip() # Exclude empty lines
]
expected_interval = 1.0 / calculated_frame_rate # Expected time between frames
frame_drops = [
i for i, (t1, t2) in enumerate(zip(frame_times, frame_times[1:]))
if abs(t2 - t1 - expected_interval) > 0.01 # Tolerance for irregularity
]
if frame_drops:
print(f"ERROR: Detected frame drops at frames: {frame_drops}")
else:
print("No frame drops detected.")
except Exception as e:
print(f"Error analyzing frames for drops: {e}")
else:
print("ERROR: No video stream found")
# Check for audio stream
audio_stream = next((stream for stream in metadata['streams'] if stream['codec_type'] == 'audio'), None)
if audio_stream:
# Check audio codec
audio_codec = audio_stream.get('codec_name')
if audio_codec == 'pcm_s16le':
print("Audio codec: WAV (PCM)")
else:
print(f"ERROR: Audio codec is NOT WAV (PCM) (Found: {audio_codec})")
# Check sample rate
sample_rate = audio_stream.get('sample_rate')
if sample_rate == "44100":
print("Audio sample rate: 44.1 kHz")
else:
print(f"ERROR: Audio sample rate is NOT 44.1 kHz (Found: {sample_rate} Hz)")
else:
print("ERROR: No audio stream found")
# Check synchronization
if video_stream and audio_stream:
video_start_pts = float(video_stream.get('start_time', 0))
audio_start_pts = float(audio_stream.get('start_time', 0))
if abs(video_start_pts - audio_start_pts) < 0.01: # Tolerance for synchronization
print("Video and audio are synchronized.")
else:
print(f"ERROR: Video and audio are NOT synchronized. Start difference: {abs(video_start_pts - audio_start_pts):.3f} seconds")
else:
print("ERROR: Could not determine synchronization (missing video or audio streams).")
# Example usage
if __name__ == "__main__":
check_video_file(file_path)
</syntaxhighlight>
</syntaxhighlight>