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FFmpeg

FFmpeg provides a set of command line tools to process audio and video media files.

Commands are located in /usr/local/ffmpeg<version>/bin and libraries are required by other packages. In DSM 7.0+, they are located in /volume1/@appstore/ffmpeg<version>/bin.

Versioned symbolic links are made available through /usr/local/bin, one pair per installed version (no unversioned ffmpeg/ffprobe link):

  • ffmpeg4, ffmpeg5, ffmpeg6, ffmpeg7, ffmpeg8
  • ffprobe4, ffprobe5, ffprobe6, ffprobe7, ffprobe8
ls -l /usr/local/bin/ff*
# ffmpeg8  -> /var/packages/ffmpeg8/target/bin/ffmpeg8
# ffprobe8 -> /var/packages/ffmpeg8/target/bin/ffprobe8
# ...

Package Information

Property Value
Package Name ffmpeg4, ffmpeg5, ffmpeg6, ffmpeg7, ffmpeg8
Upstream ffmpeg.org
License LGPL/GPL

User Permissions

To access video acceleration, users must be in the videodriver group.

  • Access to the video device file is granted on a per-application basis. This allows an application such as tvheadend to be granted access to hardware acceleration when calling ffmpeg.
  • As a default user you must interact with ffmpeg acting as a user whose access was already granted or add your user account to the videodriver group.
# Check current user and groups
id $(whoami)
# Output: uid=1026(<username>) gid=100(users) groups=100(users),101(administrators)

# Add yourself to the videodriver group
sudo synogroup --member videodriver $(whoami)

# Expected output:
# Group Name: [videodriver]
# Group Type: [AUTH_LOCAL]
# Group ID:   [937]
# Group Members:
# 0:[<username>]

# Verify the change took effect
id $(whoami)
# Output should now include: groups=100(users),101(administrators),937(videodriver)

# Log out and log back in for all applications to recognize the new group membership

Alternative: Run commands as the ffmpeg service user: 

# For FFmpeg7
sudo su -s /bin/bash sc-ffmpeg7 -c 'command'

Hardware Acceleration

For Intel-based Synology devices with DSM 7.1+, hardware transcoding is available through the SynoCli Video Driver package which provides:

  • VA-API support
  • Vulkan support (kernel 5.10+ required)
  • OpenCL support

Verify FFmpeg Hardware Acceleration Support

Before validating individual acceleration paths, confirm that FFmpeg itself was built with hardware acceleration support. The frameworks are enabled at build time — if a method is missing here, FFmpeg cannot use it regardless of driver availability.

ffmpeg7 -hide_banner -hwaccels
# Hardware acceleration methods:
# vaapi    (Intel media driver)
# qsv      (Intel Quick Sync Video)
# drm      (direct render node access)
# opencl   (GPU compute filters)
# vulkan   (work-in-progress)

Validate Detection of Your GPU

lsgpu
# Output:
# card0                    Intel Broxton (Gen9)              drm:/dev/dri/card0
# └─renderD128                                               drm:/dev/dri/renderD128

Validate Intel GPU Hardware Acceleration (VA-API)

On Intel GPUs, vainfo validates that hardware video acceleration is correctly exposed through VA-API and that the Intel media driver (iHD) is functional.

/var/packages/synocli-videodriver/target/bin/vainfo
# Output:
# Trying display: drm
# libva info: VA-API version 1.22.0
# libva info: Trying to open /var/packages/synocli-videodriver/target/lib/iHD_drv_video.so
# libva info: Found init function __vaDriverInit_1_22
# libva info: va_openDriver() returns 0
# vainfo: VA-API version: 1.22 (libva 2.22.0)
# vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 24.4.4
# vainfo: Supported profile and entrypoints
#       VAProfileNone                   : VAEntrypointVideoProc
#       VAProfileMPEG2Simple            : VAEntrypointVLD
#       VAProfileH264Main               : VAEntrypointVLD
#       VAProfileH264Main               : VAEntrypointEncSlice
#       VAProfileH264High               : VAEntrypointVLD
#       VAProfileHEVCMain               : VAEntrypointVLD
#       VAProfileHEVCMain               : VAEntrypointEncSlice
#       VAProfileVP9Profile0            : VAEntrypointVLD

This output confirms:

  • The Intel GPU is detected by the kernel
  • The Intel Media Driver (iHD) is correctly installed and loadable
  • VA-API is functional and able to communicate with the GPU
  • Hardware decode, encode and video processing capabilities are exposed

Older Intel processors fall back to the legacy i965 driver: 

# vainfo: Driver version: Intel i965 driver for Intel(R) CherryView - 2.4.1

If access is restricted or non-existent (such as on virtual DSM): 

vainfo
# Trying display: drm
# error: failed to initialize display

Validate Intel Quick Sync (QSV) for Transcoding

ffmpeg7 -hide_banner -init_hw_device qsv=hw,child_device=/dev/dri/renderD128 \
  -filter_hw_device hw -i input.mp4 \
  -vf 'hwupload=extra_hw_frames=64,scale_qsv=format=nv12' \
  -c:v h264_qsv -preset veryfast output_qsv.mp4

If QSV is not properly configured: 

QSV mapping must be enabled on context creation to use QSV to OpenCL mapping.
[AVHWDeviceContext @ 0x562fdca7bbc0] QSV to OpenCL mapping not usable.

OpenCL Acceleration

Validate OpenCL hardware acceleration (only available on DSM 7+ with recent Intel processors): 

/var/packages/synocli-videodriver/target/bin/clinfo
# Output:
# Number of platforms                               1
#   Platform Name                                   Intel(R) OpenCL Graphics
#   Platform Vendor                                 Intel(R) Corporation
#   Platform Version                                OpenCL 3.0

Validate available OpenCL filters: 

ffmpeg7 -hide_banner -filters | grep opencl
# ... avgblur_opencl    V->V       Apply average blur filter
# ... boxblur_opencl    V->V       Apply boxblur filter to input video
# ... nlmeans_opencl    V->V       Non-local means denoiser through OpenCL
# ... scale_opencl      V->V       Scale the input video size through OpenCL
# ... tonemap_opencl    V->V       Perform HDR to SDR conversion with tonemapping

Minimal OpenCL filter test: 

ffmpeg7 -benchmark \
  -init_hw_device opencl=ocl \
  -filter_hw_device ocl \
  -f lavfi -i testsrc=duration=10:size=1920x1080:rate=30 \
  -vf "format=nv12,hwupload,boxblur_opencl,hwdownload,format=nv12" \
  -f null -

This confirms OpenCL runtime and GPU compute path are operational.

Vulkan Acceleration

FFmpeg's Vulkan filters (libplacebo, scale_vulkan, overlay_vulkan, ...) run on the Vulkan device provided by the SynoCli Video Driver (Mesa anv). Whether they are runtime-usable depends on the Synology kernel, and there are two distinct failure tiers.

Tier 1 — Vulkan does not initialize at all (oldest models): 

/var/packages/synocli-videodriver/target/bin/vulkaninfo
# ERROR: VK_ERROR_INITIALIZATION_FAILED

ffmpeg8 -hide_banner -v verbose -init_hw_device vulkan
# [AVHWDeviceContext @ ...] Device creation failure: VK_ERROR_INITIALIZATION_FAILED
# Failed to set value 'vulkan' for option 'init_hw_device'

Tier 2 — Vulkan initializes, but filters fail (e.g. DS918+, Apollo Lake, DSM kernel 4.4.302+):

Here vulkaninfo sees the GPU and ffmpeg -init_hw_device vulkan succeeds, but any filter that uploads a frame to the GPU fails, because FFmpeg needs to export an external Vulkan semaphore for CPU↔GPU synchronization and the 4.4 kernel does not provide the required support (DRM syncobj / sync_file timeline export):

export VK_ICD_FILENAMES=/var/packages/synocli-videodriver/target/etc/vulkan/icd.d/intel_icd.x86_64.json
vulkaninfo --summary        # OK: GPU0 = Intel(R) HD Graphics 500 (APL 2), Mesa anv 23.3.6

ffmpeg8 -init_hw_device vulkan=vk:0 -filter_hw_device vk \
  -f lavfi -i testsrc=size=1920x1080:rate=25:duration=3 \
  -vf "format=yuv420p,hwupload,libplacebo=w=1280:h=720,hwdownload,format=yuv420p" -f null -
# Failed to create semaphore: VK_ERROR_INVALID_EXTERNAL_HANDLE
# [Parsed_hwupload_1] Failed to configure output pad on Parsed_hwupload_1
# Error reinitializing filters!

This is a platform/kernel limitation, not a packaging issue: libplacebo is built and loadable (ffmpeg8 -buildconf | grep libplacebo), but the Vulkan frame pipeline cannot run. It affects all Vulkan filters, not just libplacebo.

It may work on newer Synology models

Models shipping a newer kernel (5.10+, e.g. via https://github.com/007revad/Transcode_for_x25) may expose the external-semaphore support that the Vulkan filters need. If Vulkan filtering works on your NAS, please open an issue on spksrc with your model, DSM version, uname -r and the ffmpeg ... libplacebo ... result so we can document the working configurations.

For a functional HDR→SDR / GPU filtering path on current Synology kernels, use OpenCL (tonemap_opencl, see above) or VA-API, which do not require external-semaphore export.

Choosing an Acceleration Path

Acceleration Primary use case
VA-API Hardware decode/encode and basic video processing
QSV High-performance Intel video processing and encoding
OpenCL GPU-accelerated image and video compute filters
CPU Fallback / reference / maximum compatibility

Performance Comparison (CPU vs GPU)

Benchmarks on the same system using FFmpeg 7.0.3 with identical input, duration, filters and output settings:

Path FPS Speed Real time Relative to CPU
CPU 13 0.419× 23.9 s baseline
VA-API 17 0.559× 17.9 s ~1.3× faster
OpenCL 21 0.686× 14.6 s ~1.6× faster
QSV 23 0.773× 12.9 s ~1.8× faster
  • CPU: reference baseline, slowest but lowest memory usage
  • VA-API: moderate speedup, best suited for decode/encode acceleration
  • OpenCL: good acceleration for GPU-based filters, higher memory usage
  • QSV: best overall performance on Intel GPUs

Usage with Other Packages

Many media packages depend on FFmpeg:

Using FFmpeg in a package

A package selects which FFmpeg version to build against with FFMPEG_PACKAGE and includes spksrc.spk-meta.mk, which provides FFmpeg's libraries through the shared staging (see Build Architecture):

FFMPEG_PACKAGE = ffmpeg7
include ../../mk/spksrc.spk-meta.mk

The FFmpeg build itself is defined in cross/ffmpeg<major> (e.g. cross/ffmpeg7). Codecs and features are enabled there through standard FFmpeg CONFIGURE_ARGS, and the codec libraries are pulled in as dependencies, for example:

CONFIGURE_ARGS += --enable-gpl --enable-version3 --enable-shared
OPTIONAL_DEPENDS += cross/openh264 cross/libaom cross/svt-av1

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