1. What is digital video?

Digital video is a sequence of raster images shown over time, usually paired with audio and descriptive timing information. That simple definition is useful because most video problems can be located in one of four layers: the image itself, the timing, the way it is stored, or the path that carries it to a display.

Why this matters: “The video is broken” is too broad to troubleshoot. Asking whether the problem is resolution, timing, decoding, or signal transport gives you somewhere to start.

2. Pixels and raster images

A raster image is a grid of picture elements—pixels. Each pixel stores numeric color information. More pixels can describe finer detail, but they also require more storage, bandwidth, and processing.

Do not confuse a pixel in a media file with a physical pixel or projected point in a venue. A display system may scale, crop, blend, or distribute one source image across many physical outputs.

3. Resolution

Resolution describes the width and height of a raster image in pixels. 1920 × 1080, for example, contains 1,920 columns and 1,080 rows. Resolution does not tell you physical size by itself: the same image can appear on a phone, a monitor, or a large wall.

Choose a working resolution by asking where the media will go. Sending much more detail than the output can show may make playback harder without improving the result. Sending too little can expose softness or scaling artifacts.

4. Aspect ratio

Aspect ratio is the relationship between width and height. 16:9 is common for contemporary screens, but installations often use unusual canvases. A mismatched source and surface must be handled by one of three common fit modes:

  • contain shows the complete image and may leave empty space;
  • cover fills the surface and crops the image;
  • stretch fills both dimensions but distorts the image.

Keep important text and faces away from the edges when the final mapping is not yet known.

5. Framerate

Framerate describes how many images are presented each second. Common values include 23.976, 24, 25, 29.97, 30, 50, and 59.94/60 frames per second. Higher framerates can make motion smoother, but they increase processing and data requirements.

A file, software timeline, capture device, and display chain do not always agree. Conversions can create repeated or dropped frames. Match the delivery environment when possible, then test with the actual playback computer.

6. Bit depth

Bit depth describes how many numerical levels are available for each color channel. More levels can preserve smoother gradients and more room for adjustment. The entire workflow must support the chosen depth; a high-bit-depth source can still be reduced by an application, output connection, or display.

For most first tests, reliable playback and a correct signal path matter more than maximizing bit depth.

7. Color spaces and practical color management

A color space defines how stored numbers correspond to visible color. Camera, editing, web, broadcast, and projection workflows may use different assumptions. A mismatch can make an image look washed out, too dark, or unexpectedly saturated.

Begin with a documented, consistent workflow. Export a short test containing black, white, saturated colors, gradients, faces if relevant, and the darkest detail you need to preserve. Judge it in the actual room rather than only on a laptop.

8. Codec versus container

A codec describes how video or audio is encoded and decoded. A container packages one or more media streams with timing and metadata. H.264 is a codec; MP4 is a container. A file extension therefore does not guarantee that a particular computer can decode everything inside it.

When a file will not play, check both layers. Rewrapping changes the container without necessarily recompressing the image; transcoding creates a new encoded stream.

9. Bitrate and compression

Bitrate measures how much data is used over time. More data can preserve more detail, but codec efficiency, scene complexity, and encoder settings matter as much as a single bitrate number. Fast motion, fine texture, noise, smoke, confetti, and generated patterns are difficult to compress.

Keep a high-quality master, then create a delivery copy for the venue or platform. Do not make the delivery copy your only archive.

10. Playback and decoding

Playback is a real-time task. The computer must read the file, decode every frame, composite any effects, and send the result to an output before the next frame is due. A file that scrubs smoothly on an editing workstation may fail on a venue computer with a different decoder or graphics system.

Test a representative full-length file, not only a ten-second excerpt. Watch for heat, dropped frames, audio drift, drive speed, and loop transitions.

11. Follow the signal path

Treat the system as a chain:

media source → playback software → computer output → cable/adapter
→ switcher or capture device → processor/projector/display → visible image

Check the chain one boundary at a time. Confirm the source locally. Confirm the computer sees an output. Confirm the next device sees the computer. Replace or bypass one element at a time so the test tells you something.

12. HDMI, SDI, and capture devices

HDMI commonly carries video and audio between consumer and computer equipment. SDI is common in production environments because it is robust over longer cable runs and uses locking connectors. A capture device converts an incoming video signal into something a computer can use.

Adapters are active parts of the system, not invisible plumbing. Label known-good adapters and cables, and carry a simple test source when working in an unfamiliar venue.

13. EDID and display negotiation

EDID is information a display provides about the formats it can accept. Computers use it when deciding which resolutions and framerates to offer. Switchers, splitters, converters, and long signal chains can complicate the exchange.

If an expected output mode is missing, restart the negotiation deliberately: verify the display is powered and connected, inspect system display settings, simplify the chain, and test a conservative format before increasing complexity.

14. Network media introduction

Network media moves time-sensitive audio, video, or control data over an IP network. The cable may look familiar, but the system now depends on network addressing, capacity, congestion, and timing. “Connected to Wi-Fi” does not mean a path has enough reliable bandwidth for media.

For important realtime work, use a planned wired network where possible. Document addresses and connections, separate control and high-bandwidth media when useful, and test the actual switch and cabling.

15. NDI overview

NDI is a family of network-media tools used to send video, audio, and metadata between compatible systems. It can make routing flexible, especially among software tools and machines in the same production environment.

It does not remove the need for network design. Resolution, frame rate, encoding mode, discovery, firewall rules, switch capacity, and other traffic still affect reliability. Start with one sender and one receiver before building a larger routing graph.

16. Projection environments

Projection adds geometry, light, surface, and room conditions to the signal chain. The brightest file does not guarantee the brightest perceived image. Ambient light, projector position, throw distance, surface reflectance, black level, overlap, and viewing angle all matter.

Prepare a test pattern with labels, a grid, circles, color bars, and edge markers. Keep artistic content separate from calibration material so either can change without rebuilding the other.

Existing project documentation describes Gallery Art Bar as a wraparound environment using nine projectors with an approximately 15,000 × 1,080 aggregate canvas, plus an optional floor projector. Those values are planning references, not a current calibration guarantee.

The Gallery Lab will eventually make this relationship spatial. Until a reviewed model and measurements are available, treat every virtual surface as approximate and verify the final work in the venue.

18. Practical delivery checklist

  • Keep an original or high-quality master.
  • Make a clearly named delivery copy.
  • Confirm resolution, aspect ratio, framerate, codec, and container.
  • Test the full duration on the intended playback computer.
  • Check loop points and audio behavior.
  • Carry a short labeled test clip and a still test pattern.
  • Document the expected signal path and required adapters.
  • Bring a second copy on separate storage when practical.
  • Leave time to view the result in the actual room.

19. A useful troubleshooting order

  1. Can the source file play locally?
  2. Is the playback software producing the expected output?
  3. Does the computer detect the destination?
  4. Does each device in the chain show a valid input and output?
  5. Is the display on the correct input and format?
  6. Is the issue with the whole image, timing, color, crop, or only one part of the route?

Write down what changed between tests. Reliable troubleshooting is a process of shrinking uncertainty.

20. Continue with the workshop materials

The original Video & Media Fundamentals slides and Week 1 workshop recording provide the grant-period starting point for this continuing module. This page was developed afterward as public documentation and follow-on learning infrastructure.