From d357cf2261fb83a8b189719ac78375b426cabbfa Mon Sep 17 00:00:00 2001 From: Kongqun Yang Date: Fri, 18 Mar 2016 17:50:01 -0700 Subject: [PATCH] Created An Example on Live VP8 Transcoding + Packaging (markdown) --- ...ple-on-Live-VP8-Transcoding---Packaging.md | 29 +++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 An-Example-on-Live-VP8-Transcoding---Packaging.md diff --git a/An-Example-on-Live-VP8-Transcoding---Packaging.md b/An-Example-on-Live-VP8-Transcoding---Packaging.md new file mode 100644 index 0000000..8441b72 --- /dev/null +++ b/An-Example-on-Live-VP8-Transcoding---Packaging.md @@ -0,0 +1,29 @@ + + +This example uses pipe to chain transcoding and packaging together. Another option is to use socket. + +Assuming you have a live iptv stream available at `225.1.1.8:8001` at port `8001` with interface address `172.29.46.122`. + +## Create Pipe + +``` +mkfifo pipe1 +``` + +## Transcoding Command + +``` +ffmpeg -i udp://225.1.1.8:8001?localaddr=172.29.46.122 -g 90 -speed 4 -threads 8 -c:v libvpx -f webm pipe: > pipe1 +``` + +Option `-speed 4` tells the encoder to encode really fast, sacrificing quality. This is needed otherwise ffmpeg is not fast enough to keep up with the live stream. + +## Packaging Command + +``` +packager in=pipe1,stream=audio,init_segment=livehd-audio.webm,segment_template=livehd-audio-\$Number\$.webm in=pipe1,stream=video,init_segment=livehd-video.webm,template=livehd-video-\$Number\$.webm --mpd_output livehd.mpd --profile live --dump_stream_info --min_buffer_time=10 --time_shift_buffer_depth=300 --segment_duration=3 --io_block_size 65536 +``` + +Option `-io_block_size 65536` tells packager to use an io_block_size of 65K for threaded io file. This is necessary as reading from pipe blocks until the specified number of bytes, which is specified in io_block_size for threaded io file, thus the value of io_block_size cannot be too large. + +This example cannot be easily extended to support more streams and add encryption.