How to monitor progress from ffmpeg? - ruby-on-rails

Question

I have this ffmpeg video encoder using Rails and I needed to report ffmpeg progress to the user.
How can that be done provided that I am using Linux?

Answer 1

This is the solution I reached:
def execute_ffmpeg(cmd, progress)
logger.debug "Running command #{cmd}"
command = "#{cmd} 2>&1"
progress = nil
frames = nil
fps = 25
ffmpeg = IO.popen(command)
ffmpeg.each("\r") do |line|
if frames.nil? && line =~ /Duration:(\s.?(\d*):(\d*):(\d*\.\d*))/
duration = $2.to_s + ":" + $3.to_s + ":" + $4.to_s
frames = ($4.to_i + ($3.to_i * 60) + ($2.to_i * 60 * 60)) * fps
end
if line =~ /frame=(\s.?(\d*))/
progress = $1.to_i / frames.to_i
print "Progress: #{progress}"
end
end
end

Answer 2

Thanks for the post, I modified it a little. I am using ffmpeg version 0.10.2. Here's my version:
def exec_ffmpeg src_path, dst_path
cmd = "ffmpeg -i \"%s\" -acodec libfaac -ac 2 -ab 128k -vcodec libx264 -threads 0 \"%s\" 2>&1" %
[src_path, dst_path]
puts "%s" % cmd.gsub(/2\>\&1$/,'')
puts "press 'q' to quit"
progress = nil
dur_secs = nil
frame_rate = nil
frames = 0
dur_str = '00:00:00.000'
ostr = ''
ffmpeg = IO.popen(cmd)
ffmpeg.each("\r") do |line|
if dur_secs == nil && line =~ /Duration:\s*(\d*):(\d*):(\d*\.\d*)/
dur_str = $1.to_s + ":" + $2.to_s + ":" + $3.to_s
dur_secs = ($3.to_f + ($2.to_i * 60).to_f + ($1.to_i * 360).to_f)
puts "Video Duration:" + dur_str
end
if frame_rate == nil && line =~ /Stream.+\, (\d+\.{0,1}\d{0,3}) fps\,/
frame_rate = $1.to_f
frames = dur_secs * frame_rate
puts "Total Frames: %i" % frames.to_i
puts "Frame Rate: %.3f fps" % frame_rate
end
if line =~ /frame=(\s.?(\d*))/
cframe = $1.to_i
csecs = 0
if line =~ /time=\s*(\d*):(\d*):(\d*\.\d*)/
csecs = ($3.to_f + ($2.to_i * 60).to_f + ($1.to_i * 360).to_f)
csecs_str = $1.to_s + ":" + $2.to_s + ":" + $3.to_s
elsif line =~ /time=\s*(\d*\.\d*)/
csecs $1.to_f
t = Time.at(csecs).gmtime
csecs_str = "%0.2i:%0.2i:%0.2i.%3i" % [t.hour, t.min, t.sec, t.nsec]
end
if line =~ /fps=\s*(\d*)/
cfps = $1.to_i
else
cfps = 0
end
if line =~ /bitrate=\s*(\d*\.\d*kbits)/
br = $1
else
br = "???"
end
ostr = " %3.2f%% ( %s ) #frame:%i fps:%i bitrate:%s" %
[((csecs/dur_secs)*100), csecs_str, cframe, cfps, br]
print ostr + ("\b" * (ostr.length + 4))
end
end
print "\n"
end