Eu estou tentando criar um vídeo usando uma imagem estática (.png) com arquivo de áudio (.wav) usando o FFMPEG com duração de vídeo igual à duração do áudio, mas mesmo mantendo '-shortest' & '-loop 1' como sinalizador, a duração do vídeo é sempre 2 segundos maior que a duração do áudio.
Isso está causando problemas porque, após a criação do vídeo, eu estou fundindo vários vídeos para criar um vídeo final. Agora, o que está acontecendo é que, nesse tempo extra de 2 segundos, o próximo áudio do vídeo vem, o que está causando a falta de sincronia de vídeo e áudio. Mesmo se eu atrasar o fluxo de áudio, haverá um som em branco durante a transição de um vídeo para outro.
Então, eu queria perguntar por que há dois segundos extras e como posso removê-lo. Meu comando ffmpeg:
ffmpeg -loop 1 -i imgPath -i audioPath -c:v libx264 -c:a aac -strict experimental -pix_fmt yuv420p -vf resolution -b:a 192k -shortest videoPath
Saída do Console:
ffmpeg version N-78598-g98a0053 Copyright (c) 2000-2016 the FFmpeg developers
built with gcc 5.3.0 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
libavutil 55. 18.100 / 55. 18.100
libavcodec 57. 24.103 / 57. 24.103
libavformat 57. 25.101 / 57. 25.101
libavdevice 57. 0.101 / 57. 0.101
libavfilter 6. 34.100 / 6. 34.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.101 / 2. 0.101
libpostproc 54. 0.100 / 54. 0.100
Input #0, png_pipe, from 'image.png':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: png, rgb24(pc), 1058x794 [SAR 3779:3781 DAR 621141:466396], 25 fps, 25 tbr, 25 tbn, 25 tbc
Guessed Channel Layout for Input Stream #1.0 : stereo
Input #1, wav, from 'audio.wav':
Duration: 00:00:15.25, bitrate: 1411 kb/s
Stream #1:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s
[libx264 @ 0068f820] using SAR=2587/2590
[libx264 @ 0068f820] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0068f820] profile High, level 3.1
[libx264 @ 0068f820] 264 - core 148 r2665 a01e339 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'video.mp4':
Metadata:
encoder : Lavf57.25.101
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 800x600 [SAR 5997273:6004228 DAR 621141:466396], q=-1--1, 25 fps, 12800 tbn, 25 tbc
Metadata:
encoder : Lavc57.24.103 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 192 kb/s
Metadata:
encoder : Lavc57.24.103 aac
Stream mapping:
Stream #0:0 -> #0:0 (png (native) -> h264 (libx264))
Stream #1:0 -> #0:1 (pcm_s16le (native) -> aac (native))
Press [q] to stop, [?] for help
frame= 47 fps=0.0 q=0.0 size= 0kB time=00:00:00.00 bitrate=N/A speed= 0x
frame= 66 fps= 66 q=28.0 size= 16kB time=00:00:00.56 bitrate= 234.8kbits/s speed=0.559x
frame= 91 fps= 60 q=28.0 size= 40kB time=00:00:01.56 bitrate= 211.2kbits/s speed=1.04x
frame= 123 fps= 61 q=28.0 size= 72kB time=00:00:02.84 bitrate= 206.6kbits/s speed=1.41x
frame= 160 fps= 64 q=28.0 size= 108kB time=00:00:04.32 bitrate= 203.9kbits/s speed=1.72x
frame= 197 fps= 65 q=28.0 size= 143kB time=00:00:05.80 bitrate= 201.8kbits/s speed=1.92x
frame= 231 fps= 66 q=28.0 size= 176kB time=00:00:07.16 bitrate= 201.3kbits/s speed=2.03x
frame= 270 fps= 67 q=28.0 size= 214kB time=00:00:08.72 bitrate= 200.6kbits/s speed=2.17x
frame= 307 fps= 68 q=28.0 size= 252kB time=00:00:10.20 bitrate= 202.6kbits/s speed=2.25x
frame= 343 fps= 68 q=28.0 size= 286kB time=00:00:11.64 bitrate= 201.6kbits/s speed=2.31x
frame= 380 fps= 69 q=28.0 size= 323kB time=00:00:13.12 bitrate= 201.6kbits/s speed=2.37x
frame= 416 fps= 69 q=28.0 size= 357kB time=00:00:14.56 bitrate= 200.9kbits/s speed=2.41x
frame= 433 fps= 68 q=-1.0 Lsize= 391kB time=00:00:17.24 bitrate= 185.6kbits/s speed= 2.7x
video:18kB audio:358kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 3.837568%
[libx264 @ 0068f820] frame I:2 Avg QP: 7.83 size: 2710
[libx264 @ 0068f820] frame P:109 Avg QP: 9.51 size: 35
[libx264 @ 0068f820] frame B:322 Avg QP:12.67 size: 27
[libx264 @ 0068f820] consecutive B-frames: 0.7% 0.5% 0.0% 98.8%
[libx264 @ 0068f820] mb I I16..4: 97.9% 0.1% 2.1%
[libx264 @ 0068f820] mb P I16..4: 0.0% 0.0% 0.0% P16..4: 0.0% 0.0% 0.0% 0.0% 0.0% skip:100.0%
[libx264 @ 0068f820] mb B I16..4: 0.0% 0.0% 0.0% B16..8: 0.1% 0.0% 0.0% direct: 0.0% skip:99.9% L0:65.9% L1:34.1% BI: 0.0%
[libx264 @ 0068f820] 8x8 transform intra:0.1% inter:28.6%
[libx264 @ 0068f820] coded y,uvDC,uvAC intra: 1.6% 2.1% 2.1% inter: 0.0% 0.0% 0.0%
[libx264 @ 0068f820] i16 v,h,dc,p: 97% 0% 3% 0%
[libx264 @ 0068f820] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 50% 0% 50% 0% 0% 0% 0% 0% 0%
[libx264 @ 0068f820] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 37% 18% 19% 3% 6% 4% 6% 2% 5%
[libx264 @ 0068f820] i8c dc,h,v,p: 98% 1% 1% 0%
[libx264 @ 0068f820] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0068f820] ref P L0: 70.5% 11.4% 9.1% 9.1%
[libx264 @ 0068f820] ref B L0: 50.2% 49.8%
[libx264 @ 0068f820] ref B L1: 99.2% 0.8%
[libx264 @ 0068f820] kb/s:8.23
[aac @ 0067e4c0] Qavg: 439.702
Você pode ver aqui que meu audio.wav Duração: 00: 00: 15.25, mas o vídeo de saída.mp4 é 00: 00: 17.24.