iterating

.gitignore

-url
+config

config.sample

+# vim: ft=sh
+# Copy this file to 'config' and adjust the variables as needed.
+#
+# NOTE: Your streaming credentials will be in this file, so you should make
+# sure unauthorized users don't have access to it:
+#
+# $ umask 077
+# $ cp config.sample config
+#
+
+# How much bandwidth you want the stream to consume. If it's not plentiful, run
+# a speed test and subtract ~100 kB/s from your upload result.
+upload_bandwidth_kibs=400
+
+# This should be fine as-is.
+audio_bitrate=192
+
+# Your streaming credentials go into this URL.
+# If you don't yet have streaming credentials, ask on IRC.
+url="rtmp://lainchan.org/show/stream?user=changeme&pass=changeme"

lainstream

+#!/usr/bin/env bash
+scriptname="$(basename "$0")"
+
+tmp_file=tmp/stream.flv
+
+fail() {
+  >&2 echo "$scriptname: $*"
+  exit 1
+}
+
+fail_usage() {
+  >&2 echo "$scriptname: $*"
+  >&2 usage
+  exit 1
+}
+
+usage() {
+cat <<EOF
+usage: $scriptname transcode|stream ...
+
+  $scriptname transcode <video file> [<subtitles file>]
+                Prepares a stream by transcoding the given video file into a
+                streamable format. The subtitles argument is optional, but
+                please consider Lainons with impaired hearing.
+
+                The transcoded file will be '$tmp_file'. After you're done
+                streaming, you will have to delete this file manually for now.
+                Technically the script could auto-delete it after the 'stream'
+                command finishes, but this would go wrong when transcoding
+                speed falls below 1x, and transcoding is expensive.
+
+  $scriptname stream
+                Transmit the transcoded file to the configured server.
+
+                You should be able to start streaming while the transcode is
+                still running. Use some common sense in deciding when/if it's
+                appropriate to start a stream based on the speed reported by
+                ffmpeg (1x or higher should be fine).
+
+EOF
+}
+
+load_config() {
+  . config
+
+  upload_bandwidth_kbits=$(( upload_bandwidth_kibs * 8 ))
+  video_bitrate=$(( $upload_bandwidth_kbits - $audio_bitrate )) 
+
+  buffer_size=$(( $video_bitrate + $audio_bitrate ))
+}
+
+transcode() {
+  if [[ $# < 1 || $# > 2 ]]; then
+    fail_usage "invalid number of arguments"
+  fi
+
+  if [[ -e "$tmp_file" ]]; then
+    fail "$tmp_file exists; is a transcode running already?"
+  fi
+
+  load_config
+
+  filter_complex="scale=-1:720"
+
+  if [[ $# > 1 ]]; then
+    filter_complex="subtitles=$(printf %q "$2"):force_style='Fontname=JMH Typewriter':fontsdir=fonts,$filter_complex"
+  fi
+
+  opts=(
+    -hide_banner
+    -threads $(nproc)
+
+    -i "$1"
+
+    # audio
+    -b:a ${audio_bitrate}k
+    -c:a aac
+    -ac 2
+
+    # video
+    -b:v ${video_bitrate}k
+    -c:v h264
+    -preset faster
+    -tune zerolatency
+    -filter_complex "$filter_complex"
+
+    # streaming
+    -maxrate ${buffer_size}k
+    -bufsize ${buffer_size}k
+
+    -f flv
+    "$tmp_file"
+  )
+
+  ffmpeg "${opts[@]}"
+}
+
+stream() {
+  if [[ $# != 0 ]]; then
+    fail "too many arguments"
+  fi
+
+  load_config
+
+  opts=(
+    -hide_banner
+    -re
+    -i "$tmp_file"
+    -c copy
+    -maxrate "${buffer_size}k"
+    -bufsize "${buffer_size}k"
+    -f flv
+    "$url"
+  )
+
+  ffmpeg "${opts[@]}"
+}
+
+if [[ $# == 0 ]]; then
+  fail_usage "missing command"
+fi
+
+command="$1"
+shift
+
+case "$command" in
+  transcode) transcode "$@" ;;
+     stream) stream    "$@" ;;
+          *) fail_usage "unknown command: $command"
+esac
+

stream

-#!/usr/bin/env bash
-
-if [[ $# < 1 || $# > 3 ]]; then
-  >&2 echo "usage: $(basename "$0") <video file> [<subtitles file>] [<timestamp>]"
-  exit 1
-fi
-
-# How much bandwidth you want the stream to consume. If it's not plentiful, run
-# a speed test and subtract 100 kB/s from your upload result.
-upload_bandwidth_kibs=350
-
-upload_bandwidth_kbits=$(( upload_bandwidth_kibs * 8 ))
-
-audio_bitrate=192
-video_bitrate=$(( $upload_bandwidth_kbits - $audio_bitrate )) 
-
-buffer_size=$(( $video_bitrate + $audio_bitrate ))
-
-filter_complex="scale=-1:720"
-
-if [[ $# > 1 ]]; then
-  filter_complex="subtitles=$(printf %q "$2"):force_style='Fontname=JMH Typewriter':fontsdir=fonts,$filter_complex"
-fi
-
-input_opts=()
-
-if [[ $# > 2 ]]; then
-  input_opts+=(-ss "$3")
-fi
-
-opts=(
-  -threads $(nproc)
-  -re
-  "${input_opts[@]}"
-  -i "$1"
-
-  # audio
-  -b:a ${audio_bitrate}k
-  -c:a aac
-  -ac 2
-
-  # video
-  -b:v ${video_bitrate}k
-  -c:v h264
-  -preset faster
-  -tune zerolatency
-  -filter_complex "$filter_complex"
-
-  # streaming
-  -maxrate ${buffer_size}k
-  -bufsize ${buffer_size}k
-
-  -f flv
-  "$(cat url)"
-)
-
-echo "audio bitrate  : $audio_bitrate"
-echo "video bitrate  : $video_bitrate"
-echo "buffer size    : $buffer_size"
-echo "ffmpeg options : ${opts[@]}"
-
-ffmpeg "${opts[@]}"
-

tmp/.gitignore

+*
+!.gitignore