What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
To add a silent audio track, give FFmpeg a generated silence input with anullsrc, then explicitly map that track alongside your video. For a finite output file, a starting command is:
ffmpeg -i input.mp4
-f lavfi -i anullsrc=r=44100:cl=stereo
-map 0:v:0 -map 1:a:0
-c:v copy -c:a aac -shortest output.mp4Input 0 is the video; input 1 is generated silence. The maps select the first video stream and the silent audio stream. This is a file-muxing example, not a complete YouTube live command: a live stream also needs protocol-specific output settings and a destination. FFmpeg’s stream-selection documentation describes explicit mapping, and the anullsrc filter reference documents the null audio source and its sample-rate and channel-layout options.
What the command does—and when to use it
anullsrc generates silent audio; -map determines which streams FFmpeg sends to the output. Explicitly mapping the video and generated audio gives the output one intended audio stream, even when the video file has none.
The example above writes a finite MP4. -c:v copy copies the video without re-encoding it, while -c:a aac encodes the generated audio as AAC. Since the silence source can continue indefinitely, -shortest makes this file example end when the finite video ends. Check that the command works with your installed FFmpeg build and chosen container.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
Use the right audio mapping
When the source has no audio
Keep -map 0:v:0 -map 1:a:0: it selects the first video stream from the file and the first audio stream from the lavfi silence input. In this command, the generated source is input 1, so its audio stream is 1:a:0.
When you want to replace existing audio
Use the same explicit maps. Mapping only 0:v:0 and 1:a:0 excludes the original audio rather than sending it along with the silence. Avoid adding a map for the original audio unless you intend to include it.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Match the YouTube ingest protocol
RTMP or RTMPS
YouTube’s live encoder settings guidance lists AAC or MP3 audio for RTMP/RTMPS. It recommends 44.1 kHz and 128 kbps for stereo; these are YouTube recommendations, not FFmpeg defaults. The example generates stereo silence at 44.1 kHz and encodes AAC, but it does not specify an output bitrate or set up a live connection. Configure those for your encoder and ingest workflow. YouTube recommends RTMPS for secure transmission.
HLS
Do not treat the MP4 file example as an HLS command. YouTube’s HLS ingestion guidance specifies muxed audio and video in M2TS and AAC audio, along with segment and transport requirements. Follow those HLS-specific requirements when configuring the output; the protocol, container, and segment setup differ from the file example.
Recommended Free Tools
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Check the output before going live
- Inspect the stream structure. Use
ffprobeor a media inspector to verify that the output contains the intended video and exactly one audio stream. - Test in YouTube Live Control Room. Confirm that the ingest is healthy and that YouTube recognizes audio. YouTube Help advises: “Make sure to test before you start your live stream. Tests should include audio and movement in the video similar to what you’ll be doing in the stream.”
- Check the protocol-specific settings. For RTMP/RTMPS, verify codec, sample rate, bitrate, and audio-stream count against YouTube’s guidance. For HLS, verify the required M2TS muxing and segment setup.
YouTube’s live streaming error guidance says to provide one audio stream when the ingest has none and warns that multiple audio streams can cause ingest problems.
Troubleshoot common failures
- FFmpeg says no audio stream was selected: Recheck input order and maps. In the example, the silence source is input 1, so select
1:a:0. - The original audio is still present: Remove any map that selects the source file’s audio. Map the video from input 0 and silence from input 1.
- A file keeps growing or does not finish: Bound the generated silence to the finite video, for example with
-shortestin a file workflow or an explicit duration appropriate to the task. Do not copy this file command unchanged into a long-running live output. - YouTube reports an audio problem: Check the ingest protocol, codec, sample rate, and number of audio streams. Apply HLS-specific requirements if using HLS rather than assuming RTMP conventions.
Or let it run in the cloud
If your goal is a continuous YouTube stream from uploaded videos rather than an FFmpeg command you manage, StreamNeo runs the stream from the cloud: upload a recording or build a playlist, add your YouTube stream key once, and go live. Nothing has to stay on at home; it plays your uploaded video, not a camera feed. Any quality up to 4K 60fps streams as uploaded at one flat price per slot. If YouTube drops the stream, StreamNeo automatically recovers. The first day is free with no card. Monthly is $9.99 per month. Start your free day with StreamNeo.
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
