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• How can I crop multiple areas in each frame of the video using ffmpeg ?

  23 juin 2020, par Rick K.

  For each frame I want to crop multiple areas using ffmpeg but I am not sure how to proceed.

  


  This is what I have done to crop one part of the image,

  


  fmpeg -i video.mp4 -filter:v "fps=1,crop=759:41:33:99,scale=128:44" %d.png


  


  This is one frame of the video,

  


  

  


  The above command crops the number one row or first position from the image. Likewise I want to crop all the positions or rows from this frame. I tried passing multiple crop statements but that doesn't seem to work. What else I can try ?

  


• How to trim video by multiple frame numbers then concatenate using FFMPEG

  31 août 2020, par puneet18

  Using following code, I'm able to trim video by time :

  


  ffmpeg -i input.mp4 -filter_complex \
"[0:v]trim=60:65,setpts=PTS-STARTPTS[v0]; \
 [0:a]atrim=60:65,asetpts=PTS-STARTPTS[a0]; \
 [0:v]trim=120:125,setpts=PTS-STARTPTS[v1];
 [0:a]atrim=120:125,asetpts=PTS-STARTPTS[a1]; \
 [v0][a0][v1][a1]concat=n=2:v=1:a=1[out]" \
-map "[out]" output.mp4


  


  Above code trim video from 60-65 sec & 120-125sec then concatenate in output.mp4 file.

  


  Need to know how to trim video by using frame number and concatenate.

  


  ---

  


  Is it possible to get the time by using Frame Number and fps ?

  


  frame_1_start = 100 #Frame Number
frame_1_end   = 200 #Frame Number
frame_2_start = 450 #Frame Number
frame_3_end   = 700 #Frame Number
fps = 20 # Frame per second

time_x_1 = frame_1_start/fps
time_x_2 = frame_1_end/fps
time_y_1 = frame_2_start/fps
time_y_2 = frame_2_end/fps

ffmpeg -i input.mp4 -filter_complex \
"[0:v]trim=#{time_x_1}:#{time_x_2},setpts=PTS-STARTPTS[v0]; \
 [0:a]atrim=#{time_x_1}:#{time_x_2},asetpts=PTS-STARTPTS[a0]; \
 [0:v]trim=#{time_y_1}:#{time_y_2},setpts=PTS-STARTPTS[v1];
 [0:a]atrim=#{time_y_1}:#{time_y_2},asetpts=PTS-STARTPTS[a1]; \
 [v0][a0][v1][a1]concat=n=2:v=1:a=1[out]" \
-map "[out]" output.mp4


  


• How to apply multiple filters on a frame by AVFilterGraph of FFMPEG in c++

  26 juillet 2022, par hameed abbasi

  I'm trying to do a "crop" and then "eq" filter on an AVFrame but seems i don't understand AVFiltergraph syntax. here is the code :

  


  AVFrame *FFmpegDecoder::cropFrame(AVFrame *frame, int left, int top, int right, int bottom) {
AVFilterContext *buffersink_ctx;
AVFilterContext *buffersrc_ctx;
AVFilterGraph *filter_graph = avfilter_graph_alloc();
AVFrame *f = av_frame_alloc();
AVFilterInOut *inputs = NULL, *outputs = NULL;
char args[512];
int ret;
auto out_w = frame->width - left - right;
auto out_h = frame->height - top - bottom;
snprintf(args, sizeof(args),
         "buffer=video_size=%dx%d:pix_fmt=%d:time_base=1/1:pixel_aspect=0/1[src];"
         "[src]crop=x=%d:y=%d:out_w=%d:out_h=%d[cropped];"
         "[cropped]eq=brightness=0.06:saturation=2:contrast=1[out];"
         "[out]buffersink",
         frame->width, frame->height, frame->format,
         left, top, out_w, out_h);
ret = avfilter_graph_parse2(filter_graph, args, &inputs, &outputs);
if (ret < 0) return NULL;
assert(inputs == NULL && outputs == NULL);
ret = avfilter_graph_config(filter_graph, NULL);
if (ret < 0) return NULL;

buffersrc_ctx = avfilter_graph_get_filter(filter_graph, "Parsed_buffer_0");
buffersink_ctx = avfilter_graph_get_filter(filter_graph, "Parsed_buffersink_2");
assert(buffersrc_ctx != NULL);
assert(buffersink_ctx != NULL);

av_frame_ref(f, frame);
ret = av_buffersrc_add_frame(buffersrc_ctx, f);
if (ret < 0) return NULL;
ret = av_buffersink_get_frame(buffersink_ctx, f);
if (ret < 0) return NULL;

avfilter_graph_free(&filter_graph);

return f;


  


  }

  


  In addition, i've tried this :

  


  "buffer=video_size=%dx%d:pix_fmt=%d:time_base=1/1:pixel_aspect=0/1[src] ;"

  


  "[src]crop=x=%d:y=%d:out_w=%d:out_h=%d,eq=brightness=0.06:saturation=2:contrast=1[out] ;"

  


  "[out]buffersink"

  


  but no luck.
Thanks in advance.