我在下面嘗試過，但它只顯示背景視頻。
background_video = ffmpeg.input( "input.mp4")
overlay_video = ffmpeg.input(f'{frames_folder}*.png', pattern_type='glob', framerate=25)
subprocess = ffmpeg.overlay(
background_video,
overlay_video,
).filter("setsar", sar=1)
我還嘗試將幀序列組合成 .webm/.mov 視頻，但透明度丟失了。視頻以黑色為背景。
Ps - 幀大小與背景視頻大小相同。所以不需要縮放。
編輯
我嘗試了@Rotem 的建議
首先嘗試使用單個 PNG 影像
overlay_video = ffmpeg.input('test-frame.png')
它不適用于 OpenCV 生成的幀，但適用于任何其他 png 影像。這很奇怪，當我手動查看這些框架檔案夾時，它顯示空白影像（鏈接到我的框架檔案夾）。但是如果我將這些幀轉換成視頻（見下文），它會正確顯示我在每一幀上繪制的內容。
output_options = {
'crf': 20,
'preset': 'slower',
'movflags': 'faststart',
'pix_fmt': 'yuv420p'
}
ffmpeg.input(f'{frames_folder}*.png', pattern_type='glob', framerate=25 , reinit_filter=0).output(
'movie.avi',
**output_options
).global_args('-report').run()
嘗試從所有 PNG 影像創建視頻而不疊加
它按預期作業，唯一的問題是透明度。有沒有辦法創建透明背景視頻？我試過 .webm/.mov/.avi 但沒有成功。
添加 .global_args('-report') 并檢查日志檔案
Report written to "ffmpeg-20221119-110731.log"
Log level: 48
ffmpeg version 5.1 Copyright (c) 2000-2022 the FFmpeg developers
built with Apple clang version 13.1.6 (clang-1316.0.21.2.5)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/5.1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-neon
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
Input #0, image2, from './frames/*.png':
Duration: 00:00:05.00, start: 0.000000, bitrate: N/A
Stream #0:0: Video: png, rgba(pc), 1920x1080, 25 fps, 25 tbr, 25 tbn
Codec AVOption crf (Select the quality for constant quality mode) specified for output file #0 (movie.avi) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
Codec AVOption preset (Configuration preset) specified for output file #0 (movie.avi) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
Stream mapping:
Stream #0:0 -> #0:0 (png (native) -> mpeg4 (native))
Press [q] to stop, [?] for help
Output #0, avi, to 'movie.avi':
Metadata:
ISFT : Lavf59.27.100
Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p(tv, progressive), 1920x1080, q=2-31, 200 kb/s, 25 fps, 25 tbn
Metadata:
encoder : Lavc59.37.100 mpeg4
Side data:
cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
frame= 125 fps= 85 q=31.0 Lsize= 491kB time=00:00:05.00 bitrate= 804.3kbits/s speed=3.39x
video:482kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.772174%
繪制框架我在下面使用。
for i in range(num_frames):
transparent_img = np.zeros((height, width, 4), dtype=np.uint8)
cv2.line(transparent_img, (x1,y1), (x2,y2) ,(255, 255, 255), thickness=1, lineType=cv2.LINE_AA)
self.frames.append(transparent_img)
## To Save each frame of the video in the given folder
for i, f in enumerate(frames):
cv2.imwrite("{}/{:0{n}d}.png".format(path_to_frames, i, n=num_digits), f)
uj5u.com熱心網友回復：
以下是對你的兩個問題的回答：
要在 BGRA 影像上繪制白線，請使用
(255, 255, 255, 255)顏色而不是(255, 255, 255)。
最后一個255應用 alpha（透明度）通道值，255并使線條完全不透明。要創建具有透明背景的視頻，請嘗試：
.webm檔案型別，使用libvpx-vp9視頻編解碼器，并使用-pix_fmt yuva420p-a應用yuvaalpha（透明）通道。
這是一個“自包含”代碼示例（請閱讀評論）：
import cv2
import numpy as np
import ffmpeg
# Create synthetic MP4 video file from testing
ffmpeg.input('testsrc=size=192x108:rate=1:duration=10', f='lavfi').output('tmp.mp4').overwrite_output().run()
transparent_img = np.zeros((108, 192, 4), np.uint8)
width, height, fps = 192, 108, 1
def make_sample_image(i):
p = width//60
img = np.zeros((height, width, 4), np.uint8) # Fully transparent
cv2.putText(img, str(i), (width//2-p*10*len(str(i)), height//2 p*10), cv2.FONT_HERSHEY_DUPLEX, p, (255, 255, 255, 255), p*2) # White number
return img
# Create 10 PNG files with transparent background an white number (counter).
for i in range(1, 11):
transparent_img = make_sample_image(i)
cv2.imwrite(f'{i:03d}.png', transparent_img)
output_options = { 'vcodec' : 'libvpx-vp9', # libvpx-vp9 supports transparency.
'crf': 20,
#'preset': 'slower', # Not supported by libvpx-vp9
#'movflags': 'faststart', # Not supported by WebM
'pix_fmt': 'yuva420p' # yuva420p includes transparency.
}
frames_folder = './'
# Create video with transparency:
# reinit_filter=0 is required, only if the PNG images have different characteristics (example: some are RGB and some RGBA).
# Use d.png instead of glob pattern, becuase my Windows version of FFmpeg doesn't support glob pattern.
ffmpeg.input(f'{frames_folder}d.png', framerate=fps, reinit_filter=0).output(
'movie.webm', # WebM container supports transparency
**output_options
).global_args('-report').overwrite_output().run()
# Overlay the PNG on top of tmp.mp4
background_video = ffmpeg.input( "tmp.mp4")
overlay_video = ffmpeg.input(f'{frames_folder}d.png', framerate=fps)
subprocess = ffmpeg.overlay(
background_video,
overlay_video,
).filter("setsar", sar=1)
subprocess.output('overlay_video.webm', **output_options).global_args('-report').overwrite_output().run()
轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/537223.html
標籤：图像处理ffmpeg覆盖libavffmpeg-python
上一篇：如何洗掉陣列中的0？
下一篇：為什么卷積不適用于非標準化影像？