Regression in h264_v4l2m2m? Fragmented mp4, ffmpeg, movflag “empty_moov"

[saturn-hh]

Describe the bug

[I posteted the same question here]

I’m using ffpmeg with hardware acceleration (h264_v4l2m2m) to generate an fragmented mp4 file.

ffmpeg -hide_banner -f lavfi -i testsrc2=size=1920x1080
-vcodec h264_v4l2m2m -t 10 -bf 0
-movflags frag_keyframe+empty_moov+default_base_moof h264_v4l2m2m.mp4

Actually with the above movflags including “empty_mov” the file is generated but it's not playable in ffplay or vlc (Error: “No start code...”). This happens in 32 bit or 64 bit version of latest Raspberry Pi OS.

ffplay h264_v4l2m2m.mp4
[extract_extradata @ 0x7f6c002d80] No start code is found.B f=0/0
h264_v4l2m2m.mp4: could not find codec parameters

Using the same command In Raspbian "Buster" with h264_v4l2m2m and h264_omx the generated file is working fine. So can this be a regression from Buster to Bullseye?

Steps to reproduce the behaviour

Steps to reproduce
Generate an fragmented mp4 file with the following command:

ffmpeg -hide_banner -f lavfi -i testsrc2=size=1920x1080
-vcodec h264_v4l2m2m -t 10 -bf 0
-movflags frag_keyframe+empty_moov+default_base_moof h264_v4l2m2m.mp4

Try to play the file in with the above mentioned command and try to play the file in ffplay or VLC.

Device (s)

Raspberry Pi 4 Mod. B

System

cat /etc/rpi-issue
Raspberry Pi reference 2022-01-28
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, fbe448ccdc995d295d24c7596e5f0ef62cc2488f, stage4

vcgencmd version
Mar 24 2022 13:19:26
Copyright (c) 2012 Broadcom
version e5a963efa66a1974127860b42e913d2374139ff5 (clean) (release) (start)
uname -a
Linux raspberrypi 5.15.32-v8+ #1538 SMP PREEMPT Thu Mar 31 19:40:39 BST 2022 aarch64 GNU/Linux

Logs

mp4info h264_v4l2m2m.mp4
File:
major brand: iso5
minor version: 200
compatible brand: iso5
compatible brand: iso6
compatible brand: mp41
fast start: yes

Movie:
duration: 0 (media timescale units)
duration: 0 (ms)
time scale: 1000
fragments: yes

Found 1 Tracks
Track 1:
flags: 3 ENABLED IN-MOVIE
id: 1
type: Video
duration: 0 ms
language: und
media:
sample count: 0
timescale: 12800
duration: 0 (media timescale units)
duration: 0 (ms)
bitrate (computed): 1160.065 Kbps
sample count with fragments: 251
duration with fragments: 128000
duration with fragments: 10000 (ms)
display width: 1920.000000
display height: 1080.000000
Sample Description 0
Coding: avc1 (H.264)
Codec String: avc1.000000
AVC Profile: 0
AVC Profile Compat: 0
AVC Level: 0
AVC NALU Length Size: 0
AVC SPS: []
AVC PPS: []
Width: 1920
Height: 1080
Depth: 24

mp4info libx264.mp4

File:
major brand: iso5
minor version: 200
compatible brand: iso5
compatible brand: iso6
compatible brand: mp41
fast start: yes

Movie:
duration: 0 (media timescale units)
duration: 0 (ms)
time scale: 1000
fragments: yes

Found 1 Tracks
Track 1:
flags: 3 ENABLED IN-MOVIE
id: 1
type: Video
duration: 0 ms
language: und
media:
sample count: 0
timescale: 12800
duration: 0 (media timescale units)
duration: 0 (ms)
bitrate (computed): 5452.421 Kbps
sample count with fragments: 250
duration with fragments: 128000
duration with fragments: 10000 (ms)
display width: 1920.000000
display height: 1080.000000
Sample Description 0
Coding: avc1 (H.264)
Codec String: avc1.640028
AVC Profile: 100 (High)
AVC Profile Compat: 0
AVC Level: 40
AVC NALU Length Size: 4
AVC SPS: [67640028acb200f0044fcb80880000030008000003019078c19240]
AVC PPS: [68ebc3cb22c0]
Width: 1920
Height: 1080
Depth: 24

Generating with h264_v4l2m2m

Input #0, lavfi, from 'testsrc2=size=1920x1080':
Duration: N/A, start: 0.000000, bitrate: N/A
Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 25 tbr, 25 tbn, 25 tbc
File 'h264_v4l2m2m.mp4' already exists. Overwrite? [y/N] y
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (h264_v4l2m2m))
Press [q] to stop, [?] for help
[h264_v4l2m2m @ 0x55c29011e0] Using device /dev/video11
[h264_v4l2m2m @ 0x55c29011e0] driver 'bcm2835-codec' on card 'bcm2835-codec-encode' in mplane mode
[h264_v4l2m2m @ 0x55c29011e0] requesting formats: output=YU12 capture=H264
[h264_v4l2m2m @ 0x55c29011e0] Failed to set gop size: Invalid argument
Output #0, mp4, to 'h264_v4l2m2m.mp4':
Metadata:
encoder : Lavf58.45.100
Stream #0:0: Video: h264 (h264_v4l2m2m) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 200 kb/s, 25 fps, 12800 tbn, 25 tbc
Metadata:
encoder : Lavc58.91.100 h264_v4l2m2m
[mp4 @ 0x55c2900060] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 0x55c2900060] Encoder did not produce proper pts, making some up.
frame= 250 fps= 50 q=-0.0 Lsize= 1449kB time=00:00:09.96 bitrate=1191.7kbits/s speed= 2x
video:1416kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.321112%

Additional context

When using libx264 in the actual version of Rasberrry Pi OS 32 and 64 bit everything is fine an the file is playable.

When using movflags without “empty_mov” the file is playable but only the video in the first segment is played the following video segments are ignored. For sending the video as stream to a browser the file has to be fully fragmented.