How diff AAC samples using mediainfo

mediainfo_diff_aac_samples.md

Clone https://github.com/jlesage/docker-mediainfo

Apply patch to make mediainfo dump full AAC samples for --Details=1

diff --git a/src/mediainfo/build.sh b/src/mediainfo/build.sh
index 4183259..2de6c8d 100755
--- a/src/mediainfo/build.sh
+++ b/src/mediainfo/build.sh
@@ -79,6 +79,8 @@ rm -r \
     /tmp/MediaInfoLib/Project/zlib \
     /tmp/MediaInfoLib/Source/ThirdParty/tinyxml2 \

+sed -i 's/Trace_Activated=false/Trace_Activated=true/' /tmp/MediaInfoLib/Source/MediaInfo/Audio/File_Aac_GeneralAudio.cpp
+
 log "Downloading ZenLib package..."
 mkdir /tmp/ZenLib
 curl -# -L -f ${ZENLIB_URL} | tar xz --strip 1 -C /tmp/ZenLib

Build and run:

$ docker build -t mediainfo-dev .
...
$ docker run -v "$PWD:$PWD" -w "$PWD" --entrypoint=mediainfo --rm mediainfo-dev --Details=1 file.mp4
...
40B   raw_data_block (184 bytes)
40B    SCE - single_channel_element (151 bytes)
40B     id_syn_ele:                         0 (0x0) - (3 bits) - SCE - single_channel_element
40B     element_instance_tag:               0 (0x0) - (4 bits)
40B     individual_channel_stream (151 bytes)
40C      global_gain:                       151 (0x97) - (8 bits)
40C      ics_info (2 bytes)
40C       ics_reserved_bit:                 No
40D       window_sequence:                  3 (0x3) - (2 bits) - LONG_STOP_SEQUENCE
40D       window_shape:                     Yes
40D       max_sfb:                          38 (0x26) - (6 bits)
40E       predictor_data_present:           No
40E      section_data (9 bytes)
40E       sect_cb[g][i]:                    11 (0xB) - (4 bits)
40E       sect_len_incr:                    3 (0x03) - (5 bits)
40F       sect_cb[g][i]:                    6 (0x6) - (4 bits)
40F       sect_len_incr:                    5 (0x05) - (5 bits)
410       sect_cb[g][i]:                    11 (0xB) - (4 bits)
...

Diff samples:

$ diff -u \
  <(docker run -v $PWD:$PWD -w $PWD --entrypoint=mediainfo --rm mediainfo-dev --Details=1 a.mp4 | sed -e '1,/Second pass/ d' | cut -b 4-) \
  <(docker run -v $PWD:$PWD -w $PWD --entrypoint=mediainfo --rm mediainfo-dev --Details=1 b.mp4 | sed -e '1,/Second pass/ d' | cut -b 4-)
 --- /dev/fd/11  2025-01-27 13:52:01
+++ /dev/fd/13  2025-01-27 13:52:01
@@ -4,7 +4,7 @@
      id_syn_ele:                         0 (0x0) - (3 bits) - SCE - single_channel_element
      element_instance_tag:               0 (0x0) - (4 bits)
      individual_channel_stream (3 bytes)
-      global_gain:                       160 (0xA0) - (8 bits)
+      global_gain:                       61 (0x3D) - (8 bits)
       ics_info (2 bytes)
        ics_reserved_bit:                 No
        window_sequence:                  1 (0x1) - (2 bits) - LONG_START_SEQUENCE
 ...

Remove sed part to diff container also and you might have to adjust cut if the files are larger