def _FramesFromMp4(self, mp4_file):
host_platform = platform.GetHostPlatform()
if not host_platform.CanLaunchApplication('avconv'):
host_platform.InstallApplication('avconv')
def GetDimensions(video):
proc = subprocess.Popen(['avconv', '-i', video],
stderr=subprocess.PIPE)
dimensions = None
output = ''
for line in proc.stderr.readlines():
output += line
if 'Video:' in line:
dimensions = line.split(',')[2]
dimensions = map(int, dimensions.split()[0].split('x'))
break
proc.communicate()
assert dimensions, (
'Failed to determine video dimensions. output=%s' % output)
return dimensions
def GetFrameTimestampMs(stderr):
"""Returns the frame timestamp in integer milliseconds from the dump log.
The expected line format is:
' dts=1.715 pts=1.715\n'
We have to be careful to only read a single timestamp per call to avoid
deadlock because avconv interleaves its writes to stdout and stderr.
"""
while True:
line = ''
next_char = ''
while next_char != '\n':
next_char = stderr.read(1)
line += next_char
if 'pts=' in line:
return int(1000 * float(line.split('=')[-1]))
dimensions = GetDimensions(mp4_file)
frame_length = dimensions[0] * dimensions[1] * 3
frame_data = bytearray(frame_length)
# Use rawvideo so that we don't need any external library to parse frames.
proc = subprocess.Popen([
'avconv', '-i', mp4_file, '-vcodec', 'rawvideo', '-pix_fmt',
'rgb24', '-dump', '-loglevel', 'debug', '-f', 'rawvideo', '-'
],
stderr=subprocess.PIPE,
stdout=subprocess.PIPE)
while True:
num_read = proc.stdout.readinto(frame_data)
if not num_read:
raise StopIteration
assert num_read == len(
frame_data), 'Unexpected frame size: %d' % num_read
yield (GetFrameTimestampMs(proc.stderr),
image_util.FromRGBPixels(dimensions[0], dimensions[1],
frame_data))
def testHistogramDistanceIgnoreColor(self):
pixels = [1, 2, 3, 1, 2, 3,
1, 2, 3, 1, 2, 3]
bmp = image_util.FromRGBPixels(2, 2, pixels)
hist1 = image_util.GetColorHistogram(bmp, ignore_color=RgbaColor(1, 2, 3))
hist2 = image_util.GetColorHistogram(bmp)
self.assertEquals(hist1.Distance(hist2), 0)
def testWriteCroppedBmpToPngFile(self):
pixels = [255, 0, 0, 255, 255, 0, 0, 0, 0,
255, 255, 0, 0, 255, 0, 0, 0, 0]
orig = image_util.FromRGBPixels(3, 2, pixels)
orig = image_util.Crop(orig, 0, 0, 2, 2)
temp_file = tempfile.NamedTemporaryFile(suffix='.png').name
image_util.WritePngFile(orig, temp_file)
new_file = image_util.FromPngFile(temp_file)
self.assertTrue(image_util.AreEqual(orig, new_file, likely_equal=True))
def testCrop(self):
pixels = [0, 0, 0, 1, 0, 0, 2, 0, 0, 3, 0, 0,
0, 1, 0, 1, 1, 0, 2, 1, 0, 3, 1, 0,
0, 2, 0, 1, 2, 0, 2, 2, 0, 3, 2, 0]
bmp = image_util.FromRGBPixels(4, 3, pixels)
bmp = image_util.Crop(bmp, 1, 2, 2, 1)
self.assertEquals(2, image_util.Width(bmp))
self.assertEquals(1, image_util.Height(bmp))
image_util.GetPixelColor(bmp, 0, 0).AssertIsRGB(1, 2, 0)
image_util.GetPixelColor(bmp, 1, 0).AssertIsRGB(2, 2, 0)
self.assertEquals(image_util.Pixels(bmp), bytearray([1, 2, 0, 2, 2, 0]))
def testGetBoundingBox(self):
pixels = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
bmp = image_util.FromRGBPixels(4, 3, pixels)
box, count = image_util.GetBoundingBox(bmp, RgbaColor(1, 0, 0))
self.assertEquals(box, (1, 1, 2, 1))
self.assertEquals(count, 2)
box, count = image_util.GetBoundingBox(bmp, RgbaColor(0, 1, 0))
self.assertEquals(box, None)
self.assertEquals(count, 0)
def testHistogramIgnoreColor(self):
pixels = [1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3,
1, 2, 3, 8, 7, 6, 5, 4, 6, 1, 2, 3,
1, 2, 3, 8, 7, 6, 5, 4, 6, 1, 2, 3]
bmp = image_util.FromRGBPixels(4, 3, pixels)
hist = image_util.GetColorHistogram(bmp,
ignore_color=RgbaColor(1, 2, 3))
self.assertEquals(hist.r[1], 0)
self.assertEquals(hist.r[5], 2)
self.assertEquals(hist.r[8], 2)
self.assertEquals(hist.g[2], 0)
self.assertEquals(hist.g[4], 2)
self.assertEquals(hist.g[7], 2)
self.assertEquals(hist.b[3], 0)
self.assertEquals(hist.b[6], 4)
def testHistogramIgnoreColorTolerance(self):
pixels = [1, 2, 3, 4, 5, 6,
7, 8, 9, 8, 7, 6]
bmp = image_util.FromRGBPixels(2, 2, pixels)
hist = image_util.GetColorHistogram(
bmp, ignore_color=RgbaColor(0, 1, 2), tolerance=1)
self.assertEquals(hist.r[1], 0)
self.assertEquals(hist.r[4], 1)
self.assertEquals(hist.r[7], 1)
self.assertEquals(hist.r[8], 1)
self.assertEquals(hist.g[2], 0)
self.assertEquals(hist.g[5], 1)
self.assertEquals(hist.g[7], 1)
self.assertEquals(hist.g[8], 1)
self.assertEquals(hist.b[3], 0)
self.assertEquals(hist.b[6], 2)
self.assertEquals(hist.b[9], 1)
def testHistogram(self):
pixels = [1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3,
1, 2, 3, 8, 7, 6, 5, 4, 6, 1, 2, 3,
1, 2, 3, 8, 7, 6, 5, 4, 6, 1, 2, 3]
bmp = image_util.FromRGBPixels(4, 3, pixels)
bmp = image_util.Crop(bmp, 1, 1, 2, 2)
hist = image_util.GetColorHistogram(bmp)
for i in xrange(3):
self.assertEquals(sum(hist[i]),
image_util.Width(bmp) * image_util.Height(bmp))
self.assertEquals(hist.r[1], 0)
self.assertEquals(hist.r[5], 2)
self.assertEquals(hist.r[8], 2)
self.assertEquals(hist.g[2], 0)
self.assertEquals(hist.g[4], 2)
self.assertEquals(hist.g[7], 2)
self.assertEquals(hist.b[3], 0)
self.assertEquals(hist.b[6], 4)
