(osx) ffmpeg combining mp3 and png to mp4 resulting in mp4 with no audio

Question

I'm writing a python script that uses unix commands to do some file conversions/renderings. I'm trying to join some mp3 files with png files to get mp4s that are the picture with the mp3 playing over them. However, I've tried this with lots of different codecs and settings, and the output mp4 video never seems to have audio in it. I've looked at any answer to any question even related to ffmpeg and haven't found a solution.

Some commands I'm trying to get working currently:

ffmpeg -loop 1 -i slide_shot%d.png -i %s -c:v libx264 -pix_fmt yuv420p 
-s 720x540 -t %.3f -c:a aac -b:a 192k -shortest out%d.mp4" 
% (i, aud, slideTime, i)

ffmpeg -loop 1 -i slide_shot%d.png -i %s -shortest -t %.3f -write_xing 
0 -c:v libx264 -c:a libmp3lame -pix_fmt yuv420p -tune stillimage out%d.mp4" 
% (i, aud, slideTime, i)

ffmpeg -loop 1 -i slide_shot%d.png -i %s -shortest -t %.3f -write_xing 
0 -c:v libx264 -c:a copy -pix_fmt yuv420p -tune stillimage out%d.mp4" 
% (i, aud, slideTime, i)

I'm currently using the third one. However, none of them are giving me any audio. For reference, i is a loop iterator for naming consistency, aud is the audio filepath, and slideTime is the number of seconds the video should take.

Using this command, I'm currently getting this output in the Terminal:

ffmpeg version 3.0.2 Copyright (c) 2000-2016 the FFmpeg developers
built with Apple LLVM version 7.0.2 (clang-700.1.81)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared    
--enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-
tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --
enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --
enable-vda
libavutil      55. 17.103 / 55. 17.103
libavcodec     57. 24.102 / 57. 24.102
libavformat    57. 25.100 / 57. 25.100
libavdevice    57.  0.101 / 57.  0.101
libavfilter     6. 31.100 /  6. 31.100
libavresample   3.  0.  0 /  3.  0.  0
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 'slide_shot16.png':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: png, rgba(pc), 720x540, 25 fps, 25 tbr, 25 tbn, 25     
tbc
[mp3 @ 0x7fe4f1817e00] Skipping 0 bytes of junk at 0.
[mp3 @ 0x7fe4f1817e00] Estimating duration from bitrate, this may be inaccurate
Input #1, mp3, from 'pres_projects/Cytokine sepsis 13/data/a24x43.mp3':
Duration: 00:02:04.11, start: 0.000000, bitrate: 23 kb/s
Stream #1:0: Audio: mp3, 22050 Hz, mono, s16p, 24 kb/s
[libx264 @ 0x7fe4f1808000] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0x7fe4f1808000] profile High, level 3.0
[libx264 @ 0x7fe4f1808000] 264 - core 148 r2668 fd2c324 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:-3:-3 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=2.00:0.70 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-4 threads=12 lookahead_threads=2 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=1:1.20
Output #0, mp4, to 'out16.mp4':
Metadata:
encoder         : Lavf57.25.100
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 720x540, q=-1--1, 25 fps, 12800 tbn, 25 tbc
Metadata:
  encoder         : Lavc57.24.102 libx264
Side data:
  unknown side data type 10 (24 bytes)
Stream #0:1: Audio: mp3 (i[0][0][0] / 0x0069), 22050 Hz, mono, 24 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (png (native) -> h264 (libx264))
Stream #1:0 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame=  132 fps=0.0 q=28.0 size=40kB time=00:00:02.96 bitrate=111.8kbits/
frame=  272 fps=271 q=28.0 size=      61kB time=00:00:08.56 bitrate=  58.2kbits/
frame=  404 fps=269 q=28.0 size=     113kB time=00:00:13.84 bitrate=  66.6kbits/
frame=  537 fps=268 q=28.0 size=     132kB time=00:00:19.16 bitrate=  56.2kbits/
frame=  672 fps=268 q=28.0 size=     184kB time=00:00:24.56 bitrate=  61.3kbits/
frame=  808 fps=268 q=28.0 size=     236kB time=00:00:30.00 bitrate=  64.5kbits/
frame=  943 fps=268 q=28.0 size=     255kB time=00:00:35.40 bitrate=  59.1kbits/
frame= 1087 fps=271 q=28.0 size=     309kB time=00:00:41.16 bitrate=  61.5kbits/
frame= 1219 fps=270 q=28.0 size=     328kB time=00:00:46.44 bitrate=  57.8kbits/
frame= 1355 fps=270 q=28.0 size=     380kB time=00:00:51.88 bitrate=  60.0kbits/frame= 1494 fps=271 q=28.0 size=     400kB time=00:00:57.44 bitrate=  57.1kbits/
frame= 1632 fps=271 q=28.0 size=     453kB time=00:01:02.96 bitrate=  58.9kbits/
frame= 1767 fps=271 q=28.0 size=     472kB time=00:01:08.36 bitrate=  56.6kbits/
frame= 1893 fps=269 q=28.0 size=     523kB time=00:01:13.40 bitrate=  58.4kbits/
frame= 2020 fps=268 q=28.0 size=     541kB time=00:01:18.48 bitrate=  56.5kbits/
frame= 2147 fps=267 q=28.0 size=     592kB time=00:01:23.56 bitrate=  58.1kbits/
frame= 2275 fps=267 q=28.0 size=     611kB time=00:01:28.68 bitrate=  56.4kbits/
frame= 2401 fps=266 q=28.0 size=     661kB time=00:01:33.72 bitrate=  57.8kbits/
frame= 2528 fps=265 q=28.0 size=     680kB time=00:01:38.80 bitrate=  56.4kbits/
frame= 2654 fps=264 q=28.0 size=     731kB time=00:01:43.84 bitrate=  57.6kbits/
frame= 2781 fps=264 q=28.0 size=     749kB time=00:01:48.92 bitrate=  56.3kbits/
frame= 2906 fps=263 q=28.0 size=     799kB time=00:01:53.92 bitrate=  57.5kbits/
frame= 3033 fps=263 q=28.0 size=     818kB time=00:01:59.00 bitrate=  56.3kbits/
frame= 3102 fps=261 q=-1.0 Lsize=     983kB time=00:02:04.08 bitrate=  64.9kbits/s speed=10.5x    
video:505kB audio:364kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 13.169518%
[libx264 @ 0x7fe4f1808000] frame I:13    Avg QP:14.07  size: 33159
[libx264 @ 0x7fe4f1808000] frame P:782   Avg QP: 6.24  size:    36
[libx264 @ 0x7fe4f1808000] frame B:2307  Avg QP: 9.67  size:    25
[libx264 @ 0x7fe4f1808000] consecutive B-frames:  0.8%  0.0%  0.0% 9 9.2%
[libx264 @ 0x7fe4f1808000] mb I  I16..4: 44.1% 26.2% 29.6%
[libx264 @ 0x7fe4f1808000] 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 @ 0x7fe4f1808000] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  0.1%  0.0%  0.0%  direct: 0.0%  skip:99.9%  L0:40.4% L1:59.6% BI: 0.0%
[libx264 @ 0x7fe4f1808000] 8x8 transform intra:26.1% inter:77.7%
[libx264 @ 0x7fe4f1808000] coded y,uvDC,uvAC intra: 23.8% 9.6% 8.1% inter: 0.0% 0.0% 0.0%
[libx264 @ 0x7fe4f1808000] i16 v,h,dc,p: 60% 33%  7%  0%
[libx264 @ 0x7fe4f1808000] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 57% 12% 29%  0%  0%  0%  0%  0%  2%
[libx264 @ 0x7fe4f1808000] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 36% 29% 14%  2%  3%  4%  4%  3%  4%
[libx264 @ 0x7fe4f1808000] i8c dc,h,v,p: 74% 21%  5%  0%
[libx264 @ 0x7fe4f1808000] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x7fe4f1808000] ref P L0: 95.4%  1.1%  3.5%
[libx264 @ 0x7fe4f1808000] ref B L0:  8.5% 90.2%  1.3%
[libx264 @ 0x7fe4f1808000] kb/s:33.31

Has anyone ran into a similar problem, and if so, how did you go about fixing it? Thanks in advance for looking at my question.

Answer 1

QuickTime* does not decode MP3 audio in MP4 container. Windows Media Player also has issues, but will only decode some audio sample rates. VLC and mpv work fine. Some solutions:

• Use a better player such as VLC or mpv.
• Output to a different container format such as .mov .
• Re-encode the audio to AAC.

More information:
ffmpeg merging mp3, mp4, no sound with copy codec

_{* Tested with QuickTime 10.4 on OS X 10.11.5.}