chrjxj · January 26, 2020 11:42 · Mar 18, 2018 · Aug 22, 2017 · Aug 22, 2017 · May 17, 2017
diff --git a/python-ffmpeg.py b/python-ffmpeg.py
@@ -51,4 +51,28 @@ def read_frame(fileloc,frame,fps,num_frame,t_w,t_h) :
     out, err = ffmpeg.communicate()
     if(err) : print('error',err); return None;
     video = np.fromstring(out, dtype='uint8').reshape((num_frame,t_h,t_w,3)) #NHWC
-    return video
+    return video
+
+def write_frames(frames,filepath) :
+    assert( frames.dtype == 'uint8' )
+
+    n, h, w, c = frames.shape
+    pix_fmt = 'rgb24' if c == 3 else 'gray'
+
+    # adopted from http://zulko.github.io/blog/2013/09/27/read-and-write-video-frames-in-python-using-ffmpeg/
+    command = [ 'ffmpeg',
+                '-loglevel', 'fatal',
+                '-y', # (optional) overwrite output file if it exists
+                '-f', 'rawvideo',
+                '-vcodec','rawvideo',
+                '-s', '%dx%d'%(w,h), # size of one frame
+                '-pix_fmt', pix_fmt,
+                '-r', '24', # frames per second
+                '-i', '-', # The imput comes from a pipe
+                '-an', # Tells FFMPEG not to expect any audio
+               '-vcodec', 'libx264',
+                filepath ]
+    ffmpeg = subprocess.Popen(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE )
+    out, err = ffmpeg.communicate(frames.tostring() )
+
+    if(err) : print('error',err)
diff --git a/python-ffmpeg.py b/python-ffmpeg.py
@@ -1,6 +1,9 @@
 import subprocess
+import datetime
 import numpy as np
 
+THREAD_NUM=4
+
 def get_video_info(fileloc) :
     command = ['ffprobe',
                '-v', 'fatal',
@@ -17,18 +20,35 @@ def get_video_info(fileloc) :
             'fps': float(out[2].split('/')[0])/float(out[2].split('/')[1]),
             'duration' : out[3] }
 
-def _read_frame(filename,time) :
+def get_video_frame_count(fileloc) : # This function is spearated since it is slow.
+    command = ['ffprobe',
+               '-v', 'fatal',
+               '-count_frames',
+               '-show_entries', 'stream=nb_read_frames',
+               '-of', 'default=noprint_wrappers=1:nokey=1',
+               fileloc, '-sexagesimal']
+    ffmpeg = subprocess.Popen(command, stderr=subprocess.PIPE ,stdout = subprocess.PIPE )
+    out, err = ffmpeg.communicate()
+    if(err) : print(err)
+    out = out.split('\n')
+    return {'file' : fileloc,
+            'frames' : out[0]}
+
+def read_frame(fileloc,frame,fps,num_frame,t_w,t_h) :
     command = ['ffmpeg',
-               '-loglevel', 'error',
-               '-ss', str(time), #from this time
-               '-i', filename,
-               '-vframes', str(1),          #get single frame
+               '-loglevel', 'fatal',
+               '-ss', str(datetime.timedelta(seconds=frame/fps)),
+               '-i', fileloc,
+               #'-vf', '"select=gte(n,%d)"'%(frame),
+               '-threads', str(THREAD_NUM),
+               '-vf', 'scale=%d:%d'%(t_w,t_h),
+               '-vframes', str(num_frame),
                '-f', 'image2pipe',
                '-pix_fmt', 'rgb24',
                '-vcodec', 'rawvideo', '-']
     #print(command)
     ffmpeg = subprocess.Popen(command, stderr=subprocess.PIPE ,stdout = subprocess.PIPE )
     out, err = ffmpeg.communicate()
-    if(err) : print(err)
-    image =  np.fromstring(out, dtype='uint8').reshape((960,1280,3))
-    return image
+    if(err) : print('error',err); return None;
+    video = np.fromstring(out, dtype='uint8').reshape((num_frame,t_h,t_w,3)) #NHWC
+    return video
diff --git a/python-ffmpeg.py b/python-ffmpeg.py
@@ -1,16 +1,21 @@
 import subprocess
 import numpy as np
 
-def _get_duration(filename) :
+def get_video_info(fileloc) :
     command = ['ffprobe',
-               '-v', 'error',
-               '-show_entries', 'format=duration',
+               '-v', 'fatal',
+               '-show_entries', 'stream=width,height,r_frame_rate,duration',
                '-of', 'default=noprint_wrappers=1:nokey=1',
-               filename, '-sexagesimal']
+               fileloc, '-sexagesimal']
     ffmpeg = subprocess.Popen(command, stderr=subprocess.PIPE ,stdout = subprocess.PIPE )
     out, err = ffmpeg.communicate()
     if(err) : print(err)
-    return out
+    out = out.split('\n')
+    return {'file' : fileloc,
+            'width': int(out[0]),
+            'height' : int(out[1]),
+            'fps': float(out[2].split('/')[0])/float(out[2].split('/')[1]),
+            'duration' : out[3] }
 
 def _read_frame(filename,time) :
     command = ['ffmpeg',

diff --git a/python-ffmpeg.py b/python-ffmpeg.py
@@ -1,3 +1,6 @@
+import subprocess
+import numpy as np
+
 def _get_duration(filename) :
     command = ['ffprobe',
                '-v', 'error',

diff --git a/python-ffmpeg → python-ffmpeg.py b/python-ffmpeg → python-ffmpeg.py
diff --git a/python-ffmpeg b/python-ffmpeg
@@ -0,0 +1,26 @@
+def _get_duration(filename) :
+    command = ['ffprobe',
+               '-v', 'error',
+               '-show_entries', 'format=duration',
+               '-of', 'default=noprint_wrappers=1:nokey=1',
+               filename, '-sexagesimal']
+    ffmpeg = subprocess.Popen(command, stderr=subprocess.PIPE ,stdout = subprocess.PIPE )
+    out, err = ffmpeg.communicate()
+    if(err) : print(err)
+    return out
+
+def _read_frame(filename,time) :
+    command = ['ffmpeg',
+               '-loglevel', 'error',
+               '-ss', str(time), #from this time
+               '-i', filename,
+               '-vframes', str(1),          #get single frame
+               '-f', 'image2pipe',
+               '-pix_fmt', 'rgb24',
+               '-vcodec', 'rawvideo', '-']
+    #print(command)
+    ffmpeg = subprocess.Popen(command, stderr=subprocess.PIPE ,stdout = subprocess.PIPE )
+    out, err = ffmpeg.communicate()
+    if(err) : print(err)
+    image =  np.fromstring(out, dtype='uint8').reshape((960,1280,3))
+    return image