[vlc-commits] [Git][videolan/vlc][3.0.x] packetizer: flac: fix CRC from emulated sync
Jean-Baptiste Kempf (@jbk)
gitlab at videolan.org
Sat Dec 3 15:33:47 UTC 2022
Jean-Baptiste Kempf pushed to branch 3.0.x at VideoLAN / VLC
Commits:
c2dd4bfe by Francois Cartegnie at 2022-12-02T10:52:58+01:00
packetizer: flac: fix CRC from emulated sync
also skips some memcpy
refs #27454 #27477
(cherry picked from commit c14b5aa6a7bd3aa25fa951e2b4136aff70f5702a)
- - - - -
1 changed file:
- modules/packetizer/flac.c
Changes:
=====================================
modules/packetizer/flac.c
=====================================
@@ -78,6 +78,7 @@ struct decoder_sys_t
size_t i_last_frame_size;
uint16_t crc;
+ size_t i_buf_offset; /* in final buffer before crc check / validation / retry */
size_t i_buf;
uint8_t *p_buf;
@@ -386,6 +387,7 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
p_sys->headerinfo = headerinfo;
p_sys->i_state = STATE_NEXT_SYNC;
p_sys->i_offset = FLAC_FRAME_SIZE_MIN;
+ p_sys->i_buf_offset = 0;
p_sys->crc = 0;
/* We have to read until next frame sync code to compute current frame size
@@ -461,6 +463,7 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
block_SkipBytes( &p_sys->bytestream, FLAC_HEADER_SIZE_MAX + 2 );
block_BytestreamFlush( &p_sys->bytestream );
p_sys->crc = 0;
+ p_sys->i_buf_offset = 0;
p_sys->i_offset = 0;
p_sys->i_state = STATE_NOSYNC;
p_sys->i_next_block_flags |= BLOCK_FLAG_DISCONTINUITY;
@@ -484,10 +487,12 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
}
/* Copy from previous sync point up to to current (offset) */
- block_PeekOffsetBytes( &p_sys->bytestream, 0, p_sys->p_buf, p_sys->i_offset );
+ block_PeekOffsetBytes( &p_sys->bytestream, p_sys->i_buf_offset,
+ &p_sys->p_buf[p_sys->i_buf_offset],
+ p_sys->i_offset - p_sys->i_buf_offset );
/* update crc to include this data chunk */
- for( size_t i = 0; i < p_sys->i_offset - 2; i++ )
+ for( size_t i = p_sys->i_buf_offset; i < p_sys->i_offset - 2; i++ )
p_sys->crc = flac_crc16( p_sys->crc, p_sys->p_buf[i] );
uint16_t stream_crc = GetWBE(&p_sys->p_buf[p_sys->i_offset - 2]);
@@ -497,6 +502,7 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
/* Add the 2 last bytes which were not the CRC sum, and go for next sync point */
p_sys->crc = flac_crc16( p_sys->crc, p_sys->p_buf[p_sys->i_offset - 2] );
p_sys->crc = flac_crc16( p_sys->crc, p_sys->p_buf[p_sys->i_offset - 1] );
+ p_sys->i_buf_offset = p_sys->i_offset;
p_sys->i_offset += 1;
p_sys->i_state = !pp_block ? STATE_NOSYNC : STATE_NEXT_SYNC;
break; /* continue */
@@ -513,6 +519,7 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
block_BytestreamFlush( &p_sys->bytestream );
p_sys->i_offset = 0;
p_sys->crc = 0;
+ p_sys->i_buf_offset = 0;
if( block_BytestreamRemaining(&p_sys->bytestream) > 0 || pp_block == NULL /* drain */)
p_sys->i_state = STATE_SEND_DATA;
@@ -553,6 +560,7 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
else
free( p_sys->p_buf );
+ p_sys->i_buf_offset = 0;
p_sys->i_buf = 0;
p_sys->p_buf = NULL;
p_sys->i_offset = 0;
@@ -587,6 +595,7 @@ static int Open(vlc_object_t *p_this)
p_sys->b_stream_info = false;
p_sys->i_last_frame_size = FLAC_FRAME_SIZE_MIN;
p_sys->headerinfo.i_pts = VLC_TICK_INVALID;
+ p_sys->i_buf_offset = 0;
p_sys->i_buf = 0;
p_sys->p_buf = NULL;
p_sys->i_next_block_flags = 0;
View it on GitLab: https://code.videolan.org/videolan/vlc/-/commit/c2dd4bfefe079e49db1789eb76be3885e4fc31b4
--
View it on GitLab: https://code.videolan.org/videolan/vlc/-/commit/c2dd4bfefe079e49db1789eb76be3885e4fc31b4
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