Error "Invalid audio PTS" when playing FLAC audio stream in conjunction with "--length="

mpv Information

mpv 0.37.0 Copyright © 2000-2023 mpv/MPlayer/mplayer2 projects
libplacebo version: v6.338.2
FFmpeg version: 6.1.1-3ubuntu5
FFmpeg library versions:
   libavutil       58.29.100
   libavcodec      60.31.102
   libavformat     60.16.100
   libswscale      7.5.100
   libavfilter     9.12.100
   libswresample   4.12.100

Other Information

### System Information

  Host: mint Kernel: 6.8.0-51-generic arch: x86_64 bits: 64 compiler: gcc
    v: 13.3.0 clocksource: tsc avail: hpet,acpi_pm
    parameters: BOOT_IMAGE=/casper/vmlinuz boot=casper
  Desktop: Cinnamon v: 6.4.6 tk: GTK v: 3.24.41 wm: Muffin v: 6.4.1 tools:
    avail: cinnamon-screensaver vt: 7 dm: LightDM v: 1.30.0
    Distro: Linux Mint 22.1 Xia base: Ubuntu 24.04 noble

Graphics:
  Device-1: NVIDIA GP108 [GeForce GT 1030] vendor: Gigabyte driver: nouveau
    v: kernel alternate: nvidiafb non-free: 545.xx+ status: current (as of
    2024-04; EOL~2026-12-xx) arch: Pascal code: GP10x process: TSMC 16nm
    built: 2016-2021 pcie: gen: 1 speed: 2.5 GT/s lanes: 4 link-max: gen: 3
    speed: 8 GT/s ports: active: DVI-D-1 empty: HDMI-A-1 bus-ID: 01:00.0
    chip-ID: 10de:1d01 class-ID: 0300 temp: 38.0 C
  Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: nouveau gpu: nouveau
    display-ID: :0 screens: 1
  API: EGL v: 1.5 hw: drv: nvidia nouveau platforms: device: 0 drv: nouveau
    device: 1 drv: swrast gbm: drv: nouveau surfaceless: drv: nouveau x11:
    drv: nouveau inactive: wayland
  API: OpenGL v: 4.5 compat-v: 4.3 vendor: mesa v: 24.0.9-0ubuntu0.3
    glx-v: 1.4 direct-render: yes renderer: NV138 device-ID: 10de:1d01
    memory: 1.94 GiB unified: no

Audio:
  Device-1: Intel NM10/ICH7 Family High Definition Audio
    vendor: ASUSTeK P5KPL-VM driver: snd_hda_intel v: kernel bus-ID: 00:1b.0
    chip-ID: 8086:27d8 class-ID: 0403
  API: ALSA v: k6.8.0-51-generic status: kernel-api
    tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.0.5 status: active with: 1: pipewire-pulse
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
    tools: pactl,pw-cat,pw-cli,wpctl

Info:
  services: csd-power, power-profiles-daemon, upowerd Init: systemd v: 255
    target: graphical (5) default: graphical tool: systemctl

Source of mpv:

http://archive.ubuntu.com/ubuntu noble/universe amd64 mpv amd64 0.37.0-1ubuntu4

Latest known working version:

N/A

Issue started after the following happened:

It has never worked

Expected Behavior

When I issue command mpv --term-status-msg='${path}\naudio-bitrate:${audio-bitrate}' --length=15 'https://streams.radiomast.io/ref-lossless-ogg-flac-stereo' > ~/mpv-term-status-msg-1.log 2>&1, I expect it to play for more than a split second.

Notes

This is a Radio Mast Audio reference stream, that's supposed to always produce sound. This stream CAN be played in Firefox native audio player. The "--length=15" switch is used in my radio station test script, to detect silent radio stations.

Actual Behavior

When I issue command mpv --term-status-msg='${path}\naudio-bitrate:${audio-bitrate}' --length=15 'https://streams.radiomast.io/ref-lossless-ogg-flac-stereo' > ~/mpv-term-status-msg-1.log 2>&1, it plays only for a split second.

When I change "--length=15" to "--length=60", it still plays only for a split second.

When I leave out the "--length=15" switch, and issue mpv --term-status-msg='${path}\naudio-bitrate:${audio-bitrate}' 'https://streams.radiomast.io/ref-lossless-ogg-flac-stereo' > ~/mpv-term-status-msg-2.log 2>&1 the stream plays OK

When I issue command mpv --gpu-debug --log-file=mpv-gpu-debug.log 'https://streams.radiomast.io/ref-lossless-ogg-flac-stereo' the stream plays OK as well.

I tried installing the newest MPV package mpv_0.40.0-dmo1, but failed, due to uncorrectable package dependencies.

Probable cause

The "--length=" switch does not work correctly, when playing a FLAC audio stream.

Log Files

mpv-gpu-debug.log

mpv-term-status-msg-1.log

mpv-term-status-msg-2.log

Suggestion

Perhaps the switch "--skip-correct-audio-pts", proposed by @digitalone1 in post Avoid stream jumping due to incorrect audio PTS #15425 can be implemented?

I carefully read all instruction and confirm that I did the following:

• [unable] I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• [n/a] I attached the backtrace in the case of a crash.

Start by reproducing the exact mpv command with --length=15 against the Radio Mast FLAC stream and compare it with the command without --length. Read the attached mpv-term-status-msg-1.log and mpv-term-status-msg-2.log, then review issue #15425 for related audio PTS behavior. Done means the stream plays beyond a split second while --length still limits playback as requested.