Just a note for anybody having trouble exporting audio recorded with mlv_snd. My MLV videos started with the "WAVI" chunk that describes the audio configuration, which is good:
But for some reason the "WAVI" chunk appeared last in the "IDX" index file:
When dumping the video using mlv_dump, it seems to read the chunks in the order specified in the index, so although it encountered "AUDF" chunks throughout the video, it never wrote them to the wav file, because it hadn't seen the "WAVI" audio information chunk yet. This resulted in an empty 2kB wav file.
Adding "--skip-xref" to the mlv_dump command fixed this and I recovered my 4.6MB of audio! (i.e. mlv_dump --dng --skip-xref M25-1629.MLV)
Code Select
# mlv_dump --visualize --skip-xref M25-1629.MLV
...
Processing...
[MLVI]
[RAWI][RAWC][IDNT][EXPO][LENS][RTCI][WBAL][VERS]++++++++[WAVI][NULL]
[VIDF]+++++++++++++++++++++++[AUDF]++++++++++++++++++++++[NULL]
[VIDF]++++++++++++++++[AUDF]++++++++[NULL]++++++++++++++++++++++++++
Reached end of chunk 1/1 after 947 blocks
Processed 592 video frames at 0.01 FPS (86558.85 s)
But for some reason the "WAVI" chunk appeared last in the "IDX" index file:
Code Select
# mlv_dump --visualize M25-1629.MLV
...
M25-1629.MLV File M25-1629.IDX opened (XREF)
XREF table contains 730 entries
Processing...
[MLVI]
[RAWI][RAWC][IDNT][EXPO][LENS][RTCI][WBAL][VERS]++++++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]++++[AUDF]
[VIDF]+[AUDF][WAVI]
Reached end of all files after 730 blocks
Processed 592 video frames at 0.01 FPS (86558.85 s)
Done
When dumping the video using mlv_dump, it seems to read the chunks in the order specified in the index, so although it encountered "AUDF" chunks throughout the video, it never wrote them to the wav file, because it hadn't seen the "WAVI" audio information chunk yet. This resulted in an empty 2kB wav file.
Adding "--skip-xref" to the mlv_dump command fixed this and I recovered my 4.6MB of audio! (i.e. mlv_dump --dng --skip-xref M25-1629.MLV)