The issue is how -itsscale:a works. Perhaps I'm missing some FFmpeg nuance. If so, I'd sure appreciate correction.
The command below is meant to stretch audio to attain continuous sync. ffmpeg -itsscale:a 1.0001269035532994923857868020305 ^ -i "input.mp4" -map 0:v:0 -c:v:0 copy ^ -map 0:a:0 -c:a:0 ac3 "output.mp4" The command above should duplicate every 7880-th audio sample, recode the audio, and remux the current video and the new audio. Since audio is recoded, there should be no edit list. It appears that none of that is what actually happens. Instead, the editlist shown below is created and added to the MP4. Furthermore, the editlist appears to want to drop 31 frames, but no frames should be dropped. [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Format mov,mp4,m4a,3gp,3g2,mj2 probed with size=2048 and score=100 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] ISO: File Type Major Brand: isom [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Unknown dref type 0x206c7275 size 12 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Processing st: 0, edit list 0 - media time: 2002, duration: 266122872 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Offset DTS by 2002 to make first pts zero. [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Setting codecpar->delay to 2 for stream st: 0 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Unknown dref type 0x206c7275 size 12 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Processing st: 1, edit list 0 - media time: 324580, duration: 532220352 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 276480 @ 180 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 278016 @ 181 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 279552 @ 182 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 281088 @ 183 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 282624 @ 184 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 284160 @ 185 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 285696 @ 186 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 287232 @ 187 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 288768 @ 188 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 290304 @ 189 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 291840 @ 190 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 293376 @ 191 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 294912 @ 192 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 296448 @ 193 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 297984 @ 194 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 299520 @ 195 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 301056 @ 196 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 302592 @ 197 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 304128 @ 198 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 305664 @ 199 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 307200 @ 200 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 308736 @ 201 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 310272 @ 202 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 311808 @ 203 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 313344 @ 204 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 314880 @ 205 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 316416 @ 206 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 317952 @ 207 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 319488 @ 208 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 321024 @ 209 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 322560 @ 210 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] skip 484 audio samples from curr_cts: 324096 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Unknown dref type 0x206c7275 size 12 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] Processing st: 2, edit list 0 - media time: 324580, duration: 532220352 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 276480 @ 180 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 278016 @ 181 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 279552 @ 182 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 281088 @ 183 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 282624 @ 184 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 284160 @ 185 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 285696 @ 186 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 287232 @ 187 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 288768 @ 188 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 290304 @ 189 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 291840 @ 190 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 293376 @ 191 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 294912 @ 192 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 296448 @ 193 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 297984 @ 194 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 299520 @ 195 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 301056 @ 196 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 302592 @ 197 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 304128 @ 198 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 305664 @ 199 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 307200 @ 200 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 308736 @ 201 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 310272 @ 202 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 311808 @ 203 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 313344 @ 204 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 314880 @ 205 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 316416 @ 206 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 317952 @ 207 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 319488 @ 208 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 321024 @ 209 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] drop a frame at curr_cts: 322560 @ 210 [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000026bdf80] skip 484 audio samples from curr_cts: 324096 _______________________________________________ ffmpeg-user mailing list -- [email protected] To unsubscribe send an email to [email protected]
