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avutil : remove deprecated FF_API_PALETTE_HAS_CHANGED
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- [DH] libavcodec/8bps.c
- [DH] libavcodec/ansi.c
- [DH] libavcodec/bethsoftvideo.c
- [DH] libavcodec/bfi.c
- [DH] libavcodec/bintext.c
- [DH] libavcodec/bmvvideo.c
- [DH] libavcodec/brenderpix.c
- [DH] libavcodec/c93.c
- [DH] libavcodec/cdgraphics.c
- [DH] libavcodec/cdtoons.c
- [DH] libavcodec/cinepak.c
- [DH] libavcodec/dds.c
- [DH] libavcodec/dfa.c
- [DH] libavcodec/dsicinvideo.c
- [DH] libavcodec/dxa.c
- [DH] libavcodec/flicvideo.c
- [DH] libavcodec/gemdec.c
- [DH] libavcodec/idcinvideo.c
- [DH] libavcodec/imx.c
- [DH] libavcodec/interplayvideo.c
- [DH] libavcodec/jvdec.c
- [DH] libavcodec/kmvc.c
- [DH] libavcodec/mscc.c
- [DH] libavcodec/msrle.c
- [DH] libavcodec/mss1.c
- [DH] libavcodec/msvideo1.c
- [DH] libavcodec/pafvideo.c
- [DH] libavcodec/pictordec.c
- [DH] libavcodec/psd.c
- [DH] libavcodec/qdrw.c
- [DH] libavcodec/qpeg.c
- [DH] libavcodec/qtrle.c
- [DH] libavcodec/rawdec.c
- [DH] libavcodec/rscc.c
- [DH] libavcodec/sga.c
- [DH] libavcodec/smacker.c
- [DH] libavcodec/smc.c
- [DH] libavcodec/targa.c
- [DH] libavcodec/tiertexseqv.c
- [DH] libavcodec/tmv.c
- [DH] libavcodec/tscc.c
- [DH] libavcodec/vb.c
- [DH] libavcodec/vqavideo.c
- [DH] libavcodec/yop.c
- [DH] libavutil/frame.c
- [DH] libavutil/frame.h
- [DH] libavutil/version.h
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FFMPEG : TS video copied to MP4, missing 3 first frames [closed]
21 août 2023, par Vasilis LemonidisRunning :


ffmpeg -i test.ts -fflags +genpts -c copy -y test.mp4



for this test.ts, which has 30 frames, readable by opencv, I end up with 28 frames, out of which 27 are readable by opencv. More specifically :


ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 tmp.ts 



returns 30.


ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 tmp.mp4



returns 28.


Using OpenCV in that manner


cap = cv2.VideoCapture(tmp_path)
readMat = []
while cap.isOpened():
 ret, frame = cap.read()
 if not ret:
 break
 readMat.append(frame)



I get for the ts file 30 frames, while for the mp4 27 frames.


Could someone explain why the discrepancies ? I get no error during the transformation from ts to mp4 :


ffmpeg version N-111746-gd53acf452f Copyright (c) 2000-2023 the FFmpeg developers
 built with gcc 11.3.0 (GCC)
 configuration: --ld=g++ --bindir=/bin --extra-libs='-lpthread -lm' --pkg-config-flags=--static --enable-static --enable-gpl --enable-libaom --enable-libass --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libsvtav1 --enable-libdav1d --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree --enable-cuda-nvcc --enable-cuvid --enable-nvenc --enable-libnpp 
 libavutil 58. 16.101 / 58. 16.101
 libavcodec 60. 23.100 / 60. 23.100
 libavformat 60. 10.100 / 60. 10.100
 libavdevice 60. 2.101 / 60. 2.101
 libavfilter 9. 10.100 / 9. 10.100
 libswscale 7. 3.100 / 7. 3.100
 libswresample 4. 11.100 / 4. 11.100
 libpostproc 57. 2.100 / 57. 2.100
[mpegts @ 0x4237240] DTS discontinuity in stream 0: packet 5 with DTS 306003, packet 6 with DTS 396001
Input #0, mpegts, from 'tmp.ts':
 Duration: 00:00:21.33, start: 3.400000, bitrate: 15 kb/s
 Program 1 
 Metadata:
 service_name : Service01
 service_provider: FFmpeg
 Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 300x300, 1 fps, 3 tbr, 90k tbn
Output #0, mp4, to 'test.mp4':
 Metadata:
 encoder : Lavf60.10.100
 Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 300x300, q=2-31, 1 fps, 3 tbr, 90k tbn
Stream mapping:
 Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
[out#0/mp4 @ 0x423e280] video:25kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 4.192123%
frame= 30 fps=0.0 q=-1.0 Lsize= 26kB time=00:00:21.00 bitrate= 10.3kbits/s speed=1e+04x 



Additional information


The origin of the video I am processing comes from a continuous stitching operation of still images ts videos, produced by this class
update
method :

import cv2
import os
import subprocess
from tempfile import NamedTemporaryFile
class VideoUpdater:
 def __init__(
 self, video_path: str, framerate: int, timePerFrame: Optional[int] = None
 ):
 """
 Video updater takes in a video path, and updates it using a supplied frame, based on a given framerate.
 Args:
 video_path: str: Specify the path to the video file
 framerate: int: Set the frame rate of the video
 """
 if not video_path.endswith(".mp4"):
 LOGGER.warning(
 f"File type {os.path.splitext(video_path)[1]} not supported for streaming, switching to ts"
 )
 video_path = os.path.splitext(video_path)[0] + ".mp4"

 self._ps = None
 self.env = {
 
 }
 self.ffmpeg = "/usr/bin/ffmpeg "

 self.video_path = video_path
 self.ts_path = video_path.replace(".mp4", ".ts")
 self.tfile = None
 self.framerate = framerate
 self._video = None
 self.last_frame = None
 self.curr_frame = None


 def update(self, frame: np.ndarray):
 if len(frame.shape) == 2:
 frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2BGR)
 else:
 frame = cv2.cvtColor(frame, cv2.COLOR_RGB2BGR)
 self.writeFrame(frame)

 def writeFrame(self, frame: np.ndarray):
 """
 The writeFrame function takes a frame and writes it to the video file.
 Args:
 frame: np.ndarray: Write the frame to a temporary file
 """


 tImLFrame = NamedTemporaryFile(suffix=".png")
 tVidLFrame = NamedTemporaryFile(suffix=".ts")

 cv2.imwrite(tImLFrame.name, frame)
 ps = subprocess.Popen(
 self.ffmpeg
 + rf"-loop 1 -r {self.framerate} -i {tImLFrame.name} -t {self.framerate} -vcodec libx264 -pix_fmt yuv420p -y {tVidLFrame.name}",
 env=self.env,
 shell=True,
 stdout=subprocess.PIPE,
 stderr=subprocess.PIPE,
 )
 ps.communicate()
 if os.path.isfile(self.ts_path):
 # this does not work to watch, as timestamps are not updated
 ps = subprocess.Popen(
 self.ffmpeg
 + rf'-i "concat:{self.ts_path}|{tVidLFrame.name}" -c copy -y {self.ts_path.replace(".ts", ".bak.ts")}',
 env=self.env,
 shell=True,
 stdout=subprocess.PIPE,
 stderr=subprocess.PIPE,
 )
 ps.communicate()
 shutil.move(self.ts_path.replace(".ts", ".bak.ts"), self.ts_path)

 else:
 shutil.copyfile(tVidLFrame.name, self.ts_path)
 # fixing timestamps, we dont have to wait for this operation
 ps = subprocess.Popen(
 self.ffmpeg
 + rf"-i {self.ts_path} -fflags +genpts -c copy -y {self.video_path}",
 env=self.env,
 shell=True,
 # stdout=subprocess.PIPE,
 # stderr=subprocess.PIPE,
 )
 tImLFrame.close()
 tVidLFrame.close()