Merge pull request #13 from matteodelabre/specify-output

Allow choosing the video output

README.md

@@ -20,7 +20,9 @@ reMarkable screen sharing over SSH.
 ### Options
 
 - `-p --portrait`: shows the reMarkable screen in portrait mode (the default is landscape mode, 90 degrees rotated tot the right)
-- `-d --destination`: the ssh destination of the reMarkable (default: `root@10.11.99.1`)
+- `-s --source`: the ssh destination of the reMarkable (default: `root@10.11.99.1`)
+- `-o --output`: path of the output where the video should be recorded, as understood by `ffmpeg`; if this is `-`, the video is displayed in a new window and not recorded anywhere (default: `-`)
+- `-f --format`: when recording to an output, this option is used to force the encoding format; if this is `-`, `ffmpeg`’s auto format detection based on the file extension is used (default: `-`).
 
 If you have problems, don't hesitate to [open an issue](https://github.com/rien/reStream/issues/new) or [send me an email](mailto:rien.maertens@posteo.be).
 

reStream.sh

@@ -1,8 +1,10 @@
 #!/bin/sh
 
 # default values for arguments
-ssh_host="root@10.11.99.1" # remarkable connected trough USB
+ssh_host="root@10.11.99.1" # remarkable connected through USB
 landscape=true             # rotate 90 degrees to the right
+output_path=-              # display output through ffplay
+format=-                   # automatic output format
 
 # loop through arguments and process them
 while [ $# -gt 0 ]; do
@@ -11,13 +13,23 @@ while [ $# -gt 0 ]; do
             landscape=false
             shift
             ;;
-        -d | --destination)
+        -s | --source)
             ssh_host="$2"
             shift
             shift
             ;;
+        -o | --output)
+            output_path="$2"
+            shift
+            shift
+            ;;
+        -f | --format)
+            format="$2"
+            shift
+            shift
+            ;;
         *)
-            echo "Usage: $0 [-p] [-d <destination>]"
+            echo "Usage: $0 [-p] [-s <source>] [-o <output>] [-f <format>]"
             exit 1
             ;;
     esac
@@ -59,18 +71,27 @@ fi
 if [ -z "$compress" ]; then
     echo "Your remarkable does not have lz4."
     fallback_to_gzip
-elif ! which lz4; then
+elif ! lz4 -V; then
     echo "Your host does not have lz4."
     fallback_to_gzip
 else
     decompress="lz4 -d"
 fi
 
-# calculte how much bytes the window is
+# list of ffmpeg filters to apply
+video_filters=""
+
+# store extra ffmpeg arguments in $@
+set --
+
+# calculate how much bytes the window is
 window_bytes="$((width * height * bytes_per_pixel))"
 
 # rotate 90 degrees if landscape=true
-landscape_param="$($landscape && echo '-vf transpose=1')"
+$landscape && video_filters="$video_filters,transpose=1"
+
+# set each frame presentation time to the time it is received
+video_filters="$video_filters,setpts=(RTCTIME - RTCSTART) / (TB * 1000000)"
 
 # read the first $window_bytes of the framebuffer
 head_fb0="dd if=/dev/fb0 count=1 bs=$window_bytes 2>/dev/null"
@@ -78,16 +99,30 @@ head_fb0="dd if=/dev/fb0 count=1 bs=$window_bytes 2>/dev/null"
 # loop that keeps on reading and compressing, to be executed remotely
 read_loop="while $head_fb0; do $loop_wait; done | $compress"
 
+set -- "$@" -vf "${video_filters#,}"
+
+if [ "$output_path" = - ]; then
+    output_cmd=ffplay
+else
+    output_cmd=ffmpeg
+
+    if [ "$format" != - ]; then
+        set -- "$@" -f "$format"
+    fi
+
+    set -- "$@" "$output_path"
+fi
+
 set -e # stop if an error occurs
 
 # shellcheck disable=SC2086
 ssh_cmd "$read_loop" \
     | $decompress \
-    | ffplay \
+    | "$output_cmd" \
         -vcodec rawvideo \
         -loglevel "$loglevel" \
         -f rawvideo \
         -pixel_format gray16le \
         -video_size "$width,$height" \
-        $landscape_param \
-        -i -
+        -i - \
+        "$@"