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| Requirement | Standard MP4 | fg-selective-videos-lossy.bin | |-------------|--------------|--------------------------------| | Append new video without rewriting moov atom | ❌ Difficult | ✅ Trivial (just write at end) | | Low RAM / no filesystem | ❌ Requires complex structure | ✅ Simple sequential writes | | Embedded custom metadata | ❌ Vendor boxes exist but bulky | ✅ Arbitrary binary allowed | | Power-loss resilience | ❌ Corrupts easily if not closed | ✅ More robust (no central index) |
ffplay -f h264 extracted_stream.h264 If you know the index structure, write a Python script to parse headers. Example skeleton: fg-selective-videos-lossy.bin
Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 00000000 46 47 53 56 01 00 00 00 04 00 00 00 00 00 10 00 FGSV....4...... 00000010 00 00 05 00 00 00 00 20 00 00 01 02 03 04 05 06 ....... ........ Here, 46 47 53 56 is the magic, 01 = version 1, 04 00 00 00 = 4 clips. You might ask, "Why not just use standard MP4?" The answer lies in constraints: | Requirement | Standard MP4 | fg-selective-videos-lossy
import struct with open("fg-selective-videos-lossy.bin", "rb") as f: magic = f.read(4) version = struct.unpack("<I", f.read(4))[0] # assuming little-endian num_clips = struct.unpack("<I", f.read(4))[0] # Read index table (offset, length) for each clip clips = [] for _ in range(num_clips): offset = struct.unpack("<Q", f.read(8))[0] length = struct.unpack("<Q", f.read(8))[0] clips.append((offset, length)) # Extract each clip as raw H.264 for i, (off, l) in enumerate(clips): f.seek(off) clip_data = f.read(l) with open(f"clip_i:03d.h264", "wb") as out: out.write(clip_data) 01 = version 1