Quiet Frame Decompress: Difference between revisions

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(Created page with "{{DiscussionThread |Synopsis=Page created to understand how fLaC decompresses the 0 Quiet Frame so it can be incorporated into analAI |Analysis=Key differences: # Mid-side compression |EditDate=2025-03-16 }} Issues: # Warmup does not appear in wave or raw file which I don't understand as I get the same warmup values in analAI as FLaC seems to produce. ==Instruction trace flac for analQuiet.flac== Skip metadata not pertinent <ref>(see Flac Agent Build for metadata...")
 
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| 1071 || SDC || stream decoder process || '''0xFFF8''' || FLAC__stream_decoder_process_until_end_of_stream
| 1071 || SDC || stream decoder process || '''0xFFF8''' || FLAC__stream_decoder_process_until_end_of_stream
|-
|-
| 1989 || SDC || frame_sync_ || '''0xFFF8''' || Read 7 bits. Metadata Type 0  Streaminfo
| 2041 || SDC || read_frame || Unk || read_frame_(FLAC__StreamDecoder *decoder, FLAC__bool *got_a_frame, FLAC__bool do_full_decode)
|-
|-
| 418 || BRC || FLAC__bitreader_read_raw_uint32 || '''0xFFF8''' || Read 8 bits at a time validating each byte.
| 350 || BRC || FLAC__bitreader_reset_read_crc16 || Unk || (FLAC__BitReader *br, FLAC__uint16 seed)
|-
|-
| 2009 || SDC || frame_sync_ || '''0b1111 1111''' || FF start right at end of metadata padding. 2532
| 2277 || SDC || read_frame_header_ || Unk || read_frame_header_(FLAC__StreamDecoder *decoder)byte.
|-
|-
| 2020 || SDC || frame_sync_ || '''0b1111 10''' || Right shift F8 to 0x_7c
| 381 || BDC || FLAC__bitreader_is_consumed_byte_aligned || '''0''' || (const FLAC__BitReader *br)
|-
| 2319 || SDC ||read in the raw header as bytes so we can CRC it, and parse it on the way
|if(!FLAC__bitreader_read_raw_uint32(decoder->private_->input, &x, 8))
|-
| 418 || BDC || FLAC__bitreader_read_raw_uint32 || ''variables below'' || (FLAC__BitReader *br, FLAC__uint32 *val, uint32_t bits)
|}
|}
==References==
==References==

Revision as of 18:36, 16 March 2025


EditDate 2025-03-16

Related Threads:

Page created to understand how fLaC decompresses the 0 Quiet Frame so it can be incorporated into analAI

Key differences:

  1. Mid-side compressionWeb References https://johnnywunder.info/mywiki/index.php/Quiet Frame Decompress

Issues:

  1. Warmup does not appear in wave or raw file which I don't understand as I get the same warmup values in analAI as FLaC seems to produce.

Instruction trace flac for analQuiet.flac

Skip metadata not pertinent [1]

Sync Frame
FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC
Line Number Code Package Module Value Opertion Description
1047 SDC Find Metadata 0xFFF8 FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC FFF8
1071 SDC stream decoder process 0xFFF8 FLAC__stream_decoder_process_until_end_of_stream
2041 SDC read_frame Unk read_frame_(FLAC__StreamDecoder *decoder, FLAC__bool *got_a_frame, FLAC__bool do_full_decode)
350 BRC FLAC__bitreader_reset_read_crc16 Unk (FLAC__BitReader *br, FLAC__uint16 seed)
2277 SDC read_frame_header_ Unk read_frame_header_(FLAC__StreamDecoder *decoder)byte.
381 BDC FLAC__bitreader_is_consumed_byte_aligned 0 (const FLAC__BitReader *br)
2319 SDC read in the raw header as bytes so we can CRC it, and parse it on the way if(!FLAC__bitreader_read_raw_uint32(decoder->private_->input, &x, 8))
418 BDC FLAC__bitreader_read_raw_uint32 variables below (FLAC__BitReader *br, FLAC__uint32 *val, uint32_t bits)

References

  1. ↑ (see Flac Agent Build for metadata. Assuming equivalent in pertinent details.
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