I am trying to capture video and audio from an RTSP stream using ffmpeg-4.1.3-amd64-static. The stream is produced by VLC, and contains H.264 video and AC-3 audio. I can play the stream using VLC and both video and audio work perfectly, but the command:
ffmpeg -i rtsp://10.0.0.160:7002/ -c:v copy -c:a ac3 test6.mov
produces an output file with a correct video stream and no audio stream, even though the ffmpeg output shows that both video and audio streams were detected (in the SDP, at least). Using -c:a copy makes no difference. It seems as though it is silently dropping all the input audio packets.
What am I doing wrong?
Here is some of the output, in case that is helpful (I have omitted some error messages related to failed H.264 decodes during probing, and the usual frame encoding lines):
ffmpeg version 4.1.3-static https://johnvansickle.com/ffmpeg/ Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzvbi --enable-libzimg
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
[...]
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, rtsp, from 'rtsp://10.0.0.160:7002/':
Metadata:
title : Unnamed
comment : N/A
Duration: N/A, start: 227.227222, bitrate: N/A
Stream #0:0: Video: h264 (Main), yuv420p(progressive), 1280x720, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
Stream #0:1: Audio: ac3, 48000 Hz, stereo, fltp
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (ac3 (native) -> ac3 (native))
[...]
Output #0, mov, to 'test6.mov':
Metadata:
title : Unnamed
comment : N/A
encoder : Lavf58.20.100
Stream #0:0: Video: h264 (Main) (avc1 / 0x31637661), yuv420p(progressive), 1280x720, q=2-31, 29.97 fps, 29.97 tbr, 90k tbn, 90k tbc
Stream #0:1: Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 192 kb/s
Metadata:
encoder : Lavc58.35.100 ac3
