| #!/bin/bash | |
| # Find V4L2 capture device and stream with minimal latency | |
| # Usage: ./mpv-stream.sh [device_pattern] | |
| set -e | |
| # Default device pattern (common capture card patterns) | |
| DEFAULT_PATTERNS=("capture" "video" "usb" "cam" "card" "easycap") | |
| DEVICE_PATTERN="${1:-capture}" | |
| # Function to find V4L2 devices - returns only device path | |
| find_v4l2_device() { | |
| local pattern="$1" | |
| echo "Searching for V4L2 devices with pattern: $pattern" >&2 | |
| # Check all video devices | |
| for device in /dev/video*; do | |
| if [ -c "$device" ]; then | |
| # Use v4l2-ctl to get device info | |
| if v4l2-ctl -d "$device" --all 2>/dev/null | grep -q -i "$pattern"; then | |
| echo "Found device: $device" >&2 | |
| v4l2-ctl -d "$device" --info | head -n 5 >&2 | |
| # Return only the device path (no echo) | |
| printf "%s" "$device" | |
| return 0 | |
| fi | |
| fi | |
| done | |
| return 1 | |
| } | |
| # Function to list all available V4L2 devices | |
| list_all_devices() { | |
| echo "Available V4L2 devices:" | |
| for device in /dev/video*; do | |
| if [ -c "$device" ]; then | |
| echo "=== $device ===" | |
| v4l2-ctl -d "$device" --info 2>/dev/null | head -n 3 || true | |
| echo | |
| fi | |
| done | |
| } | |
| # Try to find device with specified pattern | |
| FOUND_DEVICE="" | |
| for pattern in "$DEVICE_PATTERN" "${DEFAULT_PATTERNS[@]}"; do | |
| echo "Trying pattern: $pattern" | |
| FOUND_DEVICE=$(find_v4l2_device "$pattern") | |
| if [ -n "$FOUND_DEVICE" ]; then | |
| break | |
| fi | |
| done | |
| # If no device found, show available devices and exit | |
| if [ -z "$FOUND_DEVICE" ]; then | |
| echo "Error: No V4L2 capture device found with pattern: $DEVICE_PATTERN" | |
| echo | |
| list_all_devices | |
| echo "Please specify a different pattern or check your device connection" | |
| exit 1 | |
| fi | |
| echo "Using device: $FOUND_DEVICE" | |
| # # Configure the V4L2 device to 1080p60 upfront so we don't need global demuxer opts | |
| if command -v v4l2-ctl >/dev/null 2>&1; then | |
| echo "Configuring $FOUND_DEVICE to 1920x1080@60..." | |
| v4l2-ctl -d "$FOUND_DEVICE" --set-fmt-video=width=1920,height=1080,pixelformat=MJPG 2>/dev/null || \ | |
| # v4l2-ctl -d "$FOUND_DEVICE" --set-fmt-video=width=1920,height=1080,pixelformat=YUYV 2>/dev/null || \ | |
| echo "Warning: Could not set pixel format to MJPG/YUYV" | |
| v4l2-ctl -d "$FOUND_DEVICE" --set-parm=60 2>/dev/null || echo "Warning: Could not set framerate to 60" | |
| fi | |
| # Check if audio is available and ensure it matches the selected V4L2 device | |
| # Prefer PulseAudio for audio capture, fallback to ALSA only if PulseAudio is unavailable or no suitable source is found | |
| AUDIO_DEVICE="" | |
| AUDIO_TYPE="" | |
| # Resolve the hardware root (USB/PCI) for a sysfs path | |
| get_hw_root() { | |
| local p="$1" | |
| while [ "$p" != "/" ]; do | |
| if [ -f "$p/idVendor" ] || [ -f "$p/vendor" ]; then | |
| echo "$p" | |
| return 0 | |
| fi | |
| p=$(dirname "$p") | |
| done | |
| echo "" | |
| } | |
| # Find ALSA card number that shares the same hardware root as the given V4L2 device | |
| find_alsa_card_for_video_device() { | |
| local video="$1" | |
| local vpath | |
| vpath=$(readlink -f "/sys/class/video4linux/$(basename "$video")/device" 2>/dev/null || true) | |
| [ -z "$vpath" ] && return 1 | |
| local vroot | |
| vroot=$(get_hw_root "$vpath") | |
| [ -z "$vroot" ] && return 1 | |
| for dev in /sys/class/sound/card*/device; do | |
| [ -e "$dev" ] || continue | |
| local cpath | |
| cpath=$(readlink -f "$dev" 2>/dev/null || true) | |
| [ -z "$cpath" ] && continue | |
| local croot | |
| croot=$(get_hw_root "$cpath") | |
| [ -z "$croot" ] && continue | |
| if [ "$croot" = "$vroot" ]; then | |
| local carddir | |
| carddir=$(basename "$(dirname "$dev")") # e.g., card2 | |
| printf "%s" "${carddir#card}" | |
| return 0 | |
| fi | |
| done | |
| return 1 | |
| } | |
| # Try PulseAudio first | |
| PULSE_DEVICE_CANDIDATE="" | |
| if command -v pactl >/dev/null 2>&1; then | |
| # Try to match PulseAudio source to V4L2 device hardware root | |
| V4L2_HW_ROOT="$(get_hw_root $(readlink -f "/sys/class/video4linux/$(basename "$FOUND_DEVICE")/device" 2>/dev/null || true))" | |
| # List all sources and try to match by USB/PCI ID in the name | |
| PULSE_MATCHED="" | |
| if [ -n "$V4L2_HW_ROOT" ]; then | |
| # Extract USB/PCI ID from the hardware root path | |
| USB_ID="$(basename "$V4L2_HW_ROOT")" | |
| # Try to find a source whose name contains the USB/PCI ID | |
| PULSE_MATCHED="$(pactl list sources | awk -v RS= -v id="$USB_ID" ' | |
| $0 ~ /Source #/ && $0 !~ /monitor/ && $0 ~ /Name:[[:space:]]+.*alsa_input/ { | |
| if ($0 ~ id) { | |
| if (match($0, /Name:[[:space:]]+([^\n]+)/, n)) { print n[1]; exit } | |
| } | |
| }' | head -n1)" | |
| fi | |
| # Fallback to first non-monitor alsa_input source if no match | |
| if [ -z "$PULSE_MATCHED" ]; then | |
| PULSE_MATCHED="$(pactl list sources | awk -v RS= ' | |
| $0 ~ /Source #/ && $0 !~ /monitor/ && $0 ~ /Name:[[:space:]]+.*alsa_input/ { | |
| if (match($0, /Name:[[:space:]]+([^\n]+)/, n)) { print n[1]; exit } | |
| }' | head -n1)" | |
| fi | |
| if [ -n "$PULSE_MATCHED" ]; then | |
| AUDIO_DEVICE="$PULSE_MATCHED" | |
| AUDIO_TYPE="pulse" | |
| fi | |
| fi | |
| # If PulseAudio is not available or no suitable source, try ALSA | |
| if [ -z "$AUDIO_DEVICE" ]; then | |
| ALSA_CARD_NUM="$(find_alsa_card_for_video_device "$FOUND_DEVICE" || true)" | |
| ALSA_DEVICE_CANDIDATE="" | |
| [ -n "$ALSA_CARD_NUM" ] && ALSA_DEVICE_CANDIDATE="plughw:$ALSA_CARD_NUM,0" | |
| if [ -n "$ALSA_DEVICE_CANDIDATE" ]; then | |
| AUDIO_DEVICE="$ALSA_DEVICE_CANDIDATE" | |
| AUDIO_TYPE="alsa" | |
| fi | |
| fi | |
| [ -n "$AUDIO_DEVICE" ] && [ -n "$AUDIO_TYPE" ] && echo "Selected audio ($AUDIO_TYPE): $AUDIO_DEVICE" | |
| # MPV options for lowest latency | |
| MPV_OPTIONS=( | |
| "--profile=low-latency" | |
| "--untimed" | |
| "--video-sync=display-resample" | |
| "--interpolation=no" | |
| "--video-latency-hacks=yes" | |
| "--opengl-swapinterval=0" | |
| "--hwdec=auto-copy" # Hardware decoding if available | |
| "--gpu-context=auto" | |
| "--cache=no" | |
| "--audio-buffer=0.01" # Very small audio buffer | |
| "--log-file=./log.txt" | |
| "--demuxer-lavf-o-add=use_wallclock_as_timestamps=yes" | |
| ) | |
| # Build the mpv command and ensure a valid audio output backend is selected | |
| MPV_CMD=("mpv" "${MPV_OPTIONS[@]}") | |
| if command -v pactl >/dev/null 2>&1; then | |
| MPV_CMD+=("--ao=pulse" "--audio-device=auto") | |
| else | |
| MPV_CMD+=("--audio-device=auto") | |
| fi | |
| # Clean up any potential whitespace in device paths | |
| FOUND_DEVICE=$(echo "$FOUND_DEVICE" | tr -d '[:space:]') | |
| printf 'Found device \n%s\n' $FOUND_DEVICE | |
| printf 'Found audio \n%s\n' $AUDIO_DEVICE | |
| printf 'Found audio type \n%s\n' $AUDIO_TYPE | |
| if [ -n "$AUDIO_DEVICE" ]; then | |
| # Clean audio device path too | |
| AUDIO_DEVICE=$(echo "$AUDIO_DEVICE" | tr -d '[:space:]') | |
| # Stream with audio | |
| echo "Starting stream with audio (lowest latency)... with $AUDIO_TYPE audio device: $AUDIO_DEVICE" | |
| if [ "$AUDIO_TYPE" = "alsa" ]; then | |
| ENABLE_LSFG=1 "${MPV_CMD[@]}" \ | |
| --aid=1 \ | |
| --audio-file="av://alsa:$AUDIO_DEVICE" \ | |
| "av://v4l2:$FOUND_DEVICE" | |
| else | |
| ENABLE_LSFG=1 "${MPV_CMD[@]}" \ | |
| --aid=1 \ | |
| --audio-file="av://pulse:$AUDIO_DEVICE" \ | |
| "av://v4l2:$FOUND_DEVICE" | |
| fi | |
| else | |
| # Stream without audio | |
| echo "Starting video-only stream (lowest latency)..." | |
| echo "Note: No audio device found. If you need audio, check your audio setup." | |
| "${MPV_CMD[@]}" \ | |
| "av://v4l2:$FOUND_DEVICE" | |
| fi |