title: FFmpeg media info incorrect when encoding aac audio track
body: <p>I recently dipped my feet into encoding with FFmpeg. It's been working fine for me apart form 1 issues I have noticed recently. When I try and re-encode an audio track to acc the media info tags are somewhat wrong. Bitrate, streamsize etc seems to be copied form the source as opposed to reading it from the new track.</p>
  
  <p>Essentially I want to copy the source video, audio and subtitles and also create an AAC version of the soundtrack for playback on devices that don't support HD audio.</p>
  
  <p>Below is an example of what I am doing:</p>
  
  <pre><code>ffmpeg -i source.mkv -map_chapters 0 -map 0:v -c:v copy -c:s copy -map 0:a -c:a:0 copy -map 0:a c:a:1 aac destination.mkv
  </code></pre>
  
  <p>This results in a media info of:</p>
  
  <pre><code>Audio #1
  ID                                       : 2
  Format                                   : MLP FBA 16-ch
  Format/Info                              : Meridian Lossless Packing FBA with 16-channel presentation
  Commercial name                          : Dolby TrueHD with Dolby Atmos
  Codec ID                                 : A_TRUEHD
  Duration                                 : 1 h 50 min
  Bit rate mode                            : Variable
  Bit rate                                 : 3 545 kb/s
  Maximum bit rate                         : 5 826 kb/s
  Channel(s)                               : 8 channels
  Channel layout                           : L R C LFE Ls Rs Lb Rb
  Sampling rate                            : 48.0 kHz
  Frame rate                               : 1 200.000 FPS (40 SPF)
  Bit depth                                : 24 bits
  Compression mode                         : Lossless
  Delay relative to video                  : 21 ms
  Stream size                              : 2.73 GiB (29%)
  Title                                    : Dolby TrueHD 7.1 (Atmos)
  Language                                 : English
  Default                                  : Yes
  Forced                                   : No
  Number of dynamic objects                : 11
  Bed channel count                        : 1 channel
  Bed channel configuration                : LFE
  
  Audio #2
  ID                                       : 3
  Format                                   : AAC LC
  Format/Info                              : Advanced Audio Codec Low Complexity
  Codec ID                                 : A_AAC-2
  Duration                                 : 1 h 50 min
  Bit rate                                 : 3 545 kb/s
  Channel(s)                               : 8 channels
  Channel layout                           : C L R Ls Rs Lb Rb LFE
  Sampling rate                            : 48.0 kHz
  Frame rate                               : 46.875 FPS (1024 SPF)
  Compression mode                         : Lossy
  Stream size                              : 2.73 GiB (29%)
  Title                                    : AAC 5.1
  Writing library                          : Lavc58.62.100 aac
  Language                                 : English
  Default                                  : Yes
  Forced                                   : No
  </code></pre>
  
  <p>As you can see the bit rate, stream size, etc is copied from the source track which is incorrect. I've tried the -map_metadata -1 but that removes the metadata without creating a new one and also removed it from all video and audio tracks which I don't want.</p>
  
  <p>Any other ideas what I am doing wrong or is this just a quirk of the software?</p>
  
  <p>Thanks in advance.</p>
  
  <p>Adding -report output trimming the lines "Writing block of size..." as the file is huge:</p>
  
  <pre><code>ffmpeg started on 2019-12-04 at 14:31:25
  Report written to "ffmpeg-20191204-143125.log"
  Log level: 48
  Command line:
  "C:\\ffmpeg\\ffmpeg-20191118-d831edc-win64-static\\bin\\ffmpeg" -i input.mkv -report -map_chapters 0 -map 0:v -c:v copy -c:s copy -map 0:a -c:a:0 copy -map 0:a -c:a:1 aac destination.mkv
  ffmpeg version git-2019-11-18-d831edc Copyright (c) 2000-2019 the FFmpeg developers
    built with gcc 9.2.1 (GCC) 20191010
    configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
    libavutil      56. 36.100 / 56. 36.100
    libavcodec     58. 62.100 / 58. 62.100
    libavformat    58. 35.100 / 58. 35.100
    libavdevice    58.  9.101 / 58.  9.101
    libavfilter     7. 66.100 /  7. 66.100
    libswscale      5.  6.100 /  5.  6.100
    libswresample   3.  6.100 /  3.  6.100
    libpostproc    55.  6.100 / 55.  6.100
  Splitting the commandline.
  Reading option '-i' ... matched as input url with argument 'input.mkv'.
  Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
  Reading option '-map_chapters' ... matched as option 'map_chapters' (set chapters mapping) with argument '0'.
  Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '0:v'.
  Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'copy'.
  Reading option '-c:s' ... matched as option 'c' (codec name) with argument 'copy'.
  Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '0:a'.
  Reading option '-c:a:0' ... matched as option 'c' (codec name) with argument 'copy'.
  Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '0:a'.
  Reading option '-c:a:1' ... matched as option 'c' (codec name) with argument 'aac'.
  Reading option 'destination.mkv' ... matched as output url.
  Finished splitting the commandline.
  Parsing a group of options: global .
  Applying option report (generate a report) with argument 1.
  Successfully parsed a group of options.
  Parsing a group of options: input url input.mkv.
  Successfully parsed a group of options.
  Opening an input file: input.mkv.
  [NULL @ 000001b290ddad00] Opening 'input.mkv' for reading
  [file @ 000001b290ddbe00] Setting default whitelist 'file,crypto'
  [matroska,webm @ 000001b290ddad00] Format matroska,webm probed with size=2048 and score=100
  st:0 removing common factor 1000000 from timebase
  st:1 removing common factor 1000000 from timebase
  [matroska,webm @ 000001b290ddad00] Before avformat_find_stream_info() pos: 5080 bytes read:32768 seeks:0 nb_streams:2
  [hevc @ 000001b290ddeb80] nal_unit_type: 32(VPS), nuh_layer_id: 0, temporal_id: 0
  [hevc @ 000001b290ddeb80] Decoding VPS
  [hevc @ 000001b290ddeb80] Main 10 profile bitstream
  [hevc @ 000001b290ddeb80] nal_unit_type: 33(SPS), nuh_layer_id: 0, temporal_id: 0
  [hevc @ 000001b290ddeb80] Decoding SPS
  [hevc @ 000001b290ddeb80] Main 10 profile bitstream
  [hevc @ 000001b290ddeb80] Decoding VUI
  [hevc @ 000001b290ddeb80] nal_unit_type: 34(PPS), nuh_layer_id: 0, temporal_id: 0
  [hevc @ 000001b290ddeb80] Decoding PPS
  [hevc @ 000001b290ddeb80] nal_unit_type: 39(SEI_PREFIX), nuh_layer_id: 0, temporal_id: 0
  [hevc @ 000001b290ddeb80] Decoding SEI
  [hevc @ 000001b290ddeb80] nal_unit_type: 39(SEI_PREFIX), nuh_layer_id: 0, temporal_id: 0
  [hevc @ 000001b290ddeb80] Decoding SEI
  [hevc @ 000001b290ddeb80] nal_unit_type: 39(SEI_PREFIX), nuh_layer_id: 0, temporal_id: 0
  [hevc @ 000001b290ddeb80] Decoding SEI
  [hevc @ 000001b290ddeb80] Skipped PREFIX SEI 5
  [matroska,webm @ 000001b290ddad00] All info found
  [matroska,webm @ 000001b290ddad00] After avformat_find_stream_info() pos: 10219 bytes read:32768 seeks:0 frames:4
  Input #0, matroska,webm, from 'input.mkv':
    Metadata:
      title           : input
      ENCODER         : Lavf58.35.100
    Duration: 01:50:06.89, start: 0.000000, bitrate: 11569 kb/s
      Chapter #0:0: start 0.000000, end 308.766792
      Metadata:
        title           : Chapter 01
      Chapter #0:1: start 308.766792, end 679.720708
      Metadata:
        title           : Chapter 02
      Chapter #0:2: start 679.720708, end 904.820583
      Metadata:
        title           : Chapter 03
      Chapter #0:3: start 904.820583, end 1282.781500
      Metadata:
        title           : Chapter 04
      Chapter #0:4: start 1282.781500, end 1487.736250
      Metadata:
        title           : Chapter 05
      Chapter #0:5: start 1487.736250, end 1846.177667
      Metadata:
        title           : Chapter 06
      Chapter #0:6: start 1846.177667, end 2116.531083
      Metadata:
        title           : Chapter 07
      Chapter #0:7: start 2116.531083, end 2443.858083
      Metadata:
        title           : Chapter 08
      Chapter #0:8: start 2443.858083, end 2731.979250
      Metadata:
        title           : Chapter 09
      Chapter #0:9: start 2731.979250, end 3178.383542
      Metadata:
        title           : Chapter 10
      Chapter #0:10: start 3178.383542, end 3636.507875
      Metadata:
        title           : Chapter 11
      Chapter #0:11: start 3636.507875, end 3867.488625
      Metadata:
        title           : Chapter 12
      Chapter #0:12: start 3867.488625, end 4208.037167
      Metadata:
        title           : Chapter 13
      Chapter #0:13: start 4208.037167, end 4502.372875
      Metadata:
        title           : Chapter 14
      Chapter #0:14: start 4502.372875, end 4853.431917
      Metadata:
        title           : Chapter 15
      Chapter #0:15: start 4853.431917, end 5267.470542
      Metadata:
        title           : Chapter 16
      Chapter #0:16: start 5267.470542, end 5543.329458
      Metadata:
        title           : Chapter 17
      Chapter #0:17: start 5543.329458, end 5847.132958
      Metadata:
        title           : Chapter 18
      Chapter #0:18: start 5847.132958, end 6150.269125
      Metadata:
        title           : Chapter 19
      Chapter #0:19: start 6150.269125, end 6606.891958
      Metadata:
        title           : Chapter 20
      Stream #0:0, 3, 1/1000: Video: hevc (Main 10), yuv420p10le(tv, bt2020nc/bt2020/smpte2084), 3840x1600 [SAR 1:1 DAR 12:5], 23.98 fps, 23.98 tbr, 1k tbn, 23.98 tbc
      Metadata:
        title           : input
        ENCODER         : Lavc58.62.100 libx265
        DURATION        : 01:50:06.891000000
      Stream #0:1(eng), 1, 1/1000: Audio: truehd, 48000 Hz, 7.1, s32 (24 bit) (default)
      Metadata:
        title           : input
        _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
        BPS-eng         : 3544728
        DURATION-eng    : 01:50:06.893000000
        NUMBER_OF_FRAMES-eng: 7928271
        NUMBER_OF_BYTES-eng: 2927455224
        _STATISTICS_WRITING_APP-eng: mkvmerge v40.0.0 ('Old Town Road + Pony') 64-bit
        _STATISTICS_WRITING_DATE_UTC-eng: 2019-11-30 10:59:25
        DURATION        : 01:50:06.893000000
  Successfully opened the file.
  Parsing a group of options: output url destination.mkv.
  Applying option map_chapters (set chapters mapping) with argument 0.
  Applying option map (set input stream mapping) with argument 0:v.
  Applying option c:v (codec name) with argument copy.
  Applying option c:s (codec name) with argument copy.
  Applying option map (set input stream mapping) with argument 0:a.
  Applying option c:a:0 (codec name) with argument copy.
  Applying option map (set input stream mapping) with argument 0:a.
  Applying option c:a:1 (codec name) with argument aac.
  Successfully parsed a group of options.
  Opening an output file: destination.mkv.
  [file @ 000001b290ea7e40] Setting default whitelist 'file,crypto'
  Successfully opened the file.
  Stream mapping:
    Stream #0:0 -&gt; #0:0 (copy)
    Stream #0:1 -&gt; #0:1 (copy)
    Stream #0:1 -&gt; #0:2 (truehd (native) -&gt; aac (native))
  Press [q] to stop, [?] for help
  cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:1 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:2 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:1 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:2 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:1 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:2 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:0 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:1 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  cur_dts is invalid st:2 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  detected 12 logical cores
  [graph_0_in_0_1 @ 000001b290dda840] Setting 'time_base' to value '1/48000'
  [graph_0_in_0_1 @ 000001b290dda840] Setting 'sample_rate' to value '48000'
  [graph_0_in_0_1 @ 000001b290dda840] Setting 'sample_fmt' to value 's32'
  [graph_0_in_0_1 @ 000001b290dda840] Setting 'channel_layout' to value '0x63f'
  [graph_0_in_0_1 @ 000001b290dda840] tb:1/48000 samplefmt:s32 samplerate:48000 chlayout:0x63f
  [format_out_0_2 @ 000001b290e0ea00] Setting 'sample_fmts' to value 'fltp'
  [format_out_0_2 @ 000001b290e0ea00] Setting 'sample_rates' to value '96000|88200|64000|48000|44100|32000|24000|22050|16000|12000|11025|8000|7350'
  [format_out_0_2 @ 000001b290e0ea00] auto-inserting filter 'auto_resampler_0' between the filter 'Parsed_anull_0' and the filter 'format_out_0_2'
  [AVFilterGraph @ 000001b290e1b3c0] query_formats: 4 queried, 6 merged, 3 already done, 0 delayed
  [auto_resampler_0 @ 000001b290e0fe80] [SWR @ 000001b291232000] Using fltp internally between filters
  [auto_resampler_0 @ 000001b290e0fe80] ch:8 chl:7.1 fmt:s32 r:48000Hz -&gt; ch:8 chl:7.1 fmt:fltp r:48000Hz
  [matroska @ 000001b290dfba40] get_metadata_duration returned: 6606893000
  [matroska @ 000001b290dfba40] Write early duration from metadata = 6606893
  Output #0, matroska, to 'destination.mkv':
    Metadata:
      title           : input
      encoder         : Lavf58.35.100
      Chapter #0:0: start 0.000000, end 308.766792
      Metadata:
        title           : Chapter 01
      Chapter #0:1: start 308.766792, end 679.720708
      Metadata:
        title           : Chapter 02
      Chapter #0:2: start 679.720708, end 904.820583
      Metadata:
        title           : Chapter 03
      Chapter #0:3: start 904.820583, end 1282.781500
      Metadata:
        title           : Chapter 04
      Chapter #0:4: start 1282.781500, end 1487.736250
      Metadata:
        title           : Chapter 05
      Chapter #0:5: start 1487.736250, end 1846.177667
      Metadata:
        title           : Chapter 06
      Chapter #0:6: start 1846.177667, end 2116.531083
      Metadata:
        title           : Chapter 07
      Chapter #0:7: start 2116.531083, end 2443.858083
      Metadata:
        title           : Chapter 08
      Chapter #0:8: start 2443.858083, end 2731.979250
      Metadata:
        title           : Chapter 09
      Chapter #0:9: start 2731.979250, end 3178.383542
      Metadata:
        title           : Chapter 10
      Chapter #0:10: start 3178.383542, end 3636.507875
      Metadata:
        title           : Chapter 11
      Chapter #0:11: start 3636.507875, end 3867.488625
      Metadata:
        title           : Chapter 12
      Chapter #0:12: start 3867.488625, end 4208.037167
      Metadata:
        title           : Chapter 13
      Chapter #0:13: start 4208.037167, end 4502.372875
      Metadata:
        title           : Chapter 14
      Chapter #0:14: start 4502.372875, end 4853.431917
      Metadata:
        title           : Chapter 15
      Chapter #0:15: start 4853.431917, end 5267.470542
      Metadata:
        title           : Chapter 16
      Chapter #0:16: start 5267.470542, end 5543.329458
      Metadata:
        title           : Chapter 17
      Chapter #0:17: start 5543.329458, end 5847.132958
      Metadata:
        title           : Chapter 18
      Chapter #0:18: start 5847.132958, end 6150.269125
      Metadata:
        title           : Chapter 19
      Chapter #0:19: start 6150.269125, end 6606.891958
      Metadata:
        title           : Chapter 20
      Stream #0:0, 0, 1/1000: Video: hevc (Main 10), yuv420p10le(tv, bt2020nc/bt2020/smpte2084), 3840x1600 [SAR 1:1 DAR 12:5], q=2-31, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc
      Metadata:
        title           : input
        ENCODER         : Lavc58.62.100 libx265
        DURATION        : 01:50:06.891000000
      Stream #0:1(eng), 0, 1/1000: Audio: truehd ([255][255][255][255] / 0xFFFFFFFF), 48000 Hz, 7.1, s32 (24 bit) (default)
      Metadata:
        title           : input
        _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
        BPS-eng         : 3544728
        DURATION-eng    : 01:50:06.893000000
        NUMBER_OF_FRAMES-eng: 7928271
        NUMBER_OF_BYTES-eng: 2927455224
        _STATISTICS_WRITING_APP-eng: mkvmerge v40.0.0 ('Old Town Road + Pony') 64-bit
        _STATISTICS_WRITING_DATE_UTC-eng: 2019-11-30 10:59:25
        DURATION        : 01:50:06.893000000
      Stream #0:2(eng), 0, 1/1000: Audio: aac (LC) ([255][0][0][0] / 0x00FF), 48000 Hz, 7.1, fltp (24 bit), 469 kb/s (default)
      Metadata:
        title           : input
        _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
        BPS-eng         : 3544728
        DURATION-eng    : 01:50:06.893000000
        NUMBER_OF_FRAMES-eng: 7928271
        NUMBER_OF_BYTES-eng: 2927455224
        _STATISTICS_WRITING_APP-eng: mkvmerge v40.0.0 ('Old Town Road + Pony') 64-bit
        _STATISTICS_WRITING_DATE_UTC-eng: 2019-11-30 10:59:25
        DURATION        : 01:50:06.893000000
        encoder         : Lavc58.62.100 aac
  cur_dts is invalid st:2 (0) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
  
  ....................
  ....................
  [matroska @ 000001b290dfba40] Writing block of size 168 with pts 6606913, dts 6606913, duration 1 at relative offset 550755 in cluster at offset 9940898622. TrackNumber 2, keyframe 1
  [matroska @ 000001b290dfba40] end duration = 6606914
  [matroska @ 000001b290dfba40] stream 0 end duration = 6606912
  [matroska @ 000001b290dfba40] stream 1 end duration = 6606914
  [matroska @ 000001b290dfba40] stream 2 end duration = 6606914
  frame=158407 fps=357 q=-1.0 Lsize= 9708475kB time=01:50:06.91 bitrate=12037.7kbits/s speed=14.9x    
  video:6416483kB audio:3234397kB subtitle:0kB other streams:0kB global headers:2kB muxing overhead: 0.596787%
  Input file #0 (input.mkv):
    Input stream #0:0 (video): 158407 packets read (6570478730 bytes); 
    Input stream #0:1 (audio): 7928271 packets read (2927455224 bytes); 7928271 frames decoded (317130840 samples); 
    Total: 8086678 packets (9497933954 bytes) demuxed
  Output file #0 (destination.mkv):
    Output stream #0:0 (video): 158407 packets muxed (6570478730 bytes); 
    Output stream #0:1 (audio): 7928271 packets muxed (2927455224 bytes); 
    Output stream #0:2 (audio): 309699 frames encoded (317130840 samples); 309700 packets muxed (384567176 bytes); 
    Total: 8396378 packets (9882501130 bytes) muxed
  7928271 frames successfully decoded, 0 decoding errors
  [AVIOContext @ 000001b291230100] Statistics: 8 seeks, 39676 writeouts
  [aac @ 000001b290dff3c0] Qavg: 3839.668
  [AVIOContext @ 000001b290de4080] Statistics: 9554742230 bytes read, 0 seeks
  </code></pre>