def get_dims_from_ffmpeg_probe(
self, probe_result: typing.Dict[str, typing.Any]) -> utils.ImgDims:
"""
Extract the width and height of the video stream from probe dict and return it
"""
video_stream_data = {} # type:typing.Dict[str,typing.Any]
for stream_data in probe_result["streams"]:
if stream_data["codec_type"] == "video":
video_stream_data = stream_data
if not video_stream_data:
raise NoVideoStream
return utils.ImgDims(width=video_stream_data["width"],
height=video_stream_data["height"])
def _get_extraction_size(self, video_dims: utils.ImgDims,
preview_dims: utils.ImgDims) -> utils.ImgDims:
"""
Compute extraction dimensions.
The extract size in order to directly get the right height or width according
to what is expected for preview
:param video_dims: ImgDims object representing width and height of the video stream
:param preview_dims: ImgDims object representing width and height of the preview to generate
:return: ImgDims to use for ffmpeg video frame extraction
"""
extract_size = utils.ImgDims(-1, -1)
if video_dims.ratio() > preview_dims.ratio():
extract_size.width = preview_dims.width
else:
extract_size.height = preview_dims.height
return extract_size
def build_jpeg_preview(self,
file_path: str,
preview_name: str,
cache_path: str,
page_id: int,
extension: str = '.jpg',
size: utils.ImgDims = None,
mimetype: str = '') -> None:
"""
generate the pdf small preview
"""
if not size:
size = utils.ImgDims(256, 256)
with open(file_path, 'rb') as pdf:
# HACK - D.A. - 2017-08-11 Deactivate strict mode
# This avoid crashes when PDF are not standard
# See https://github.com/mstamy2/PyPDF2/issues/244
input_pdf = utils.get_decrypted_pdf(pdf, strict=False)
output_pdf = PdfFileWriter()
output_pdf.addPage(input_pdf.getPage(int(page_id)))
output_stream = BytesIO()
output_pdf.write(output_stream)
output_stream.seek(0, 0)
result = convert_pdf_to_jpeg(output_stream, size)
if page_id == -1:
preview_path = '{path}{file_name}{extension}'.format(
file_name=preview_name,
path=cache_path,
extension=extension)
else:
preview_path = '{path}{file_name}{extension}'.format(
file_name=preview_name,
path=cache_path,
page_id=page_id,
extension=extension)
with open(preview_path, 'wb') as jpeg:
buffer = result.read(1024)
while buffer:
jpeg.write(buffer)
buffer = result.read(1024)