How to use FFmpeg for RTMP streaming and HLS/DASH streaming media generation?

FFmpeg is an important tool for streaming media processing, supporting various streaming protocols such as RTMP, HLS, and DASH.

Push to RTMP Server

Basic Push Command

bash
# Push local file to RTMP server
ffmpeg -re -i input.mp4 -c copy -f flv rtmp://server/live/stream_key

# Real-time encoding push
ffmpeg -re -i input.mp4 -c:v libx264 -preset veryfast -b:v 1500k -c:a aac -b:a 128k -f flv rtmp://server/live/stream_key

Camera/Microphone Real-time Push

bash
# macOS camera push
ffmpeg -f avfoundation -i "0" -c:v libx264 -preset veryfast -b:v 1500k -f flv rtmp://server/live/stream_key

# Camera + microphone push
ffmpeg -f avfoundation -i "0:0" -c:v libx264 -preset veryfast -b:v 1500k -c:a aac -b:a 128k -f flv rtmp://server/live/stream_key

HLS Streaming Generation

Generate HLS Stream

bash
# Generate HLS playlist
ffmpeg -i input.mp4 -c:v libx264 -c:a aac -f hls -hls_time 10 -hls_list_size 0 output.m3u8

# Generate multi-bitrate HLS
ffmpeg -i input.mp4 \
  -vf scale=1920:1080 -c:v libx264 -b:v 5000k -f hls -hls_time 10 hls_1080p.m3u8 \
  -vf scale=1280:720 -c:v libx264 -b:v 2500k -f hls -hls_time 10 hls_720p.m3u8 \
  -vf scale=854:480 -c:v libx264 -b:v 1000k -f hls -hls_time 10 hls_480p.m3u8

HLS Parameters

• -hls_time: Duration of each segment (seconds)
• -hls_list_size: Number of segments to keep in playlist (0 means keep all)
• -hls_segment_filename: Segment file naming template
• -hls_flags: HLS special flags (e.g., delete_segments, append_list)

DASH Streaming Generation

Generate DASH Stream

bash
# Generate DASH manifest
ffmpeg -i input.mp4 -c:v libx264 -c:a aac -f dash -seg_duration 10 output.mpd

# Generate multi-bitrate DASH
ffmpeg -i input.mp4 \
  -vf scale=1920:1080 -c:v libx264 -b:v 5000k -f dash -seg_duration 10 dash_1080p.mpd \
  -vf scale=1280:720 -c:v libx264 -b:v 2500k -f dash -seg_duration 10 dash_720p.mpd

Pull Stream Processing

Pull from RTMP

bash
# Pull RTMP stream and save
ffmpeg -i rtmp://server/live/stream -c copy output.mp4

# Pull RTMP stream and transcode
ffmpeg -i rtmp://server/live/stream -c:v libx264 -preset fast -b:v 1500k -c:a aac -b:a 128k output.mp4

Pull from HLS

bash
# Download HLS stream
ffmpeg -i http://server/live/stream.m3u8 -c copy output.mp4

# Play HLS stream in real-time
ffmpeg -i http://server/live/stream.m3u8 -f null -

Streaming Optimization

Latency Optimization

bash
# Low latency push
ffmpeg -re -i input.mp4 -c:v libx264 -preset ultrafast -tune zerolatency -b:v 1500k -c:a aac -b:a 128k -f flv rtmp://server/live/stream_key

# Use GOP cache
ffmpeg -re -i input.mp4 -c:v libx264 -preset veryfast -g 25 -keyint_min 25 -b:v 1500k -c:a aac -b:a 128k -f flv rtmp://server/live/stream_key

Bitrate Control

bash
# CBR (Constant Bitrate)
ffmpeg -re -i input.mp4 -c:v libx264 -preset veryfast -b:v 1500k -maxrate 1500k -minrate 1500k -bufsize 3000k -f flv rtmp://server/live/stream_key

# VBR (Variable Bitrate)
ffmpeg -re -i input.mp4 -c:v libx264 -preset veryfast -crf 23 -maxrate 3000k -bufsize 6000k -f flv rtmp://server/live/stream_key

Common Streaming Protocols

Protocol	Use	Features
RTMP	Real-time push	Low latency, widely used for live streaming
HLS	HTTP Live Streaming	Good compatibility, supports adaptive bitrate
DASH	HTTP Live Streaming	Open standard, cross-platform support
RTSP	Real-time Streaming Protocol	Used for surveillance and IPC
UDP/RTP	Real-time Transport	Low latency, suitable for LAN

When processing streaming media, you need to select appropriate protocols and encoding parameters based on network conditions, latency requirements, and target platforms.