mirror of
https://gitee.com/openharmony/third_party_libsnd
synced 2024-11-27 03:50:29 +00:00
ogg_vorbis: Fix granule position when seeking Vorbis streams
Previously the vorbis_seek function did not take the lapped nature of Vorbis block into account when using the bisection search. Also, introduce vorbis_skip(), which can skip through packets without having to decode all the way to samples.
This commit is contained in:
Arthur Taylor
parent
ad2990ec02
commit
abe9dcc0f1
210
src/ogg_vorbis.c
210
src/ogg_vorbis.c
@ -1,4 +1,5 @@
|
||||
/*
|
||||
** Copyright (C) 2018-2021 Arthur Taylor <art@ified.ca>
|
||||
** Copyright (C) 2002-2016 Erik de Castro Lopo <erikd@mega-nerd.com>
|
||||
** Copyright (C) 2002-2005 Michael Smith <msmith@xiph.org>
|
||||
** Copyright (C) 2007 John ffitch
|
||||
@ -19,7 +20,7 @@
|
||||
*/
|
||||
|
||||
/*
|
||||
** Much of this code is based on the examples in libvorbis from the
|
||||
** Much of this code is based on the examples in libvorbis from the
|
||||
** XIPHOPHORUS Company http://www.xiph.org/ which has a BSD-style Licence
|
||||
** Copyright (c) 2002, Xiph.org Foundation
|
||||
**
|
||||
@ -78,6 +79,9 @@
|
||||
|
||||
#include "ogg.h"
|
||||
|
||||
/* How many seconds in the future to not bother bisection searching for. */
|
||||
#define VORBIS_SEEK_THRESHOLD 2
|
||||
|
||||
typedef int convert_func (SF_PRIVATE *psf, int, void *, int, int, float **) ;
|
||||
|
||||
static int vorbis_read_header (SF_PRIVATE *psf) ;
|
||||
@ -85,6 +89,8 @@ static int vorbis_write_header (SF_PRIVATE *psf, int calc_length) ;
|
||||
static int vorbis_close (SF_PRIVATE *psf) ;
|
||||
static int vorbis_command (SF_PRIVATE *psf, int command, void *data, int datasize) ;
|
||||
static int vorbis_byterate (SF_PRIVATE *psf) ;
|
||||
static int vorbis_skip (SF_PRIVATE *psf, uint64_t target_gp) ;
|
||||
static int vorbis_seek_trysearch (SF_PRIVATE *psf, uint64_t target_gp) ;
|
||||
static sf_count_t vorbis_calculate_page_duration (SF_PRIVATE *psf) ;
|
||||
static sf_count_t vorbis_seek (SF_PRIVATE *psf, int mode, sf_count_t offset) ;
|
||||
static sf_count_t vorbis_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len) ;
|
||||
@ -115,26 +121,22 @@ static STR_PAIRS vorbis_metatypes [] =
|
||||
{ SF_STR_ALBUM, "Album" },
|
||||
{ SF_STR_LICENSE, "License" },
|
||||
{ SF_STR_TRACKNUMBER, "Tracknumber" },
|
||||
{ SF_STR_GENRE, "Genre" },
|
||||
{ SF_STR_GENRE, "Genre" },
|
||||
} ;
|
||||
|
||||
typedef struct
|
||||
{ /* Count current location */
|
||||
sf_count_t loc ;
|
||||
{ /* Current granule position. */
|
||||
uint64_t loc ;
|
||||
/* Struct that stores all the static vorbis bitstream settings */
|
||||
vorbis_info vinfo ;
|
||||
/* Struct that stores all the bitstream user comments */
|
||||
vorbis_comment vcomment ;
|
||||
/* Ventral working state for the packet->PCM decoder */
|
||||
/* Central working state for the packet->PCM decoder */
|
||||
vorbis_dsp_state vdsp ;
|
||||
/* Local working space for packet->PCM decode */
|
||||
vorbis_block vblock ;
|
||||
|
||||
/* Encoding quality in range [0.0, 1.0]. */
|
||||
double quality ;
|
||||
|
||||
/* Current granule position. */
|
||||
uint64_t pcm_current ;
|
||||
/* Offset of the first samples' granule position. */
|
||||
uint64_t pcm_start ;
|
||||
/* Last valid samples' granule position. */
|
||||
@ -184,8 +186,8 @@ vorbis_read_header (SF_PRIVATE *psf)
|
||||
** Vorbis decoder.
|
||||
**
|
||||
** The next two packets in order are the comment and codebook headers.
|
||||
** They're likely large and may span multiple pages. Thus we reead
|
||||
** and submit data until we get our two pacakets, watching that no
|
||||
** They're likely large and may span multiple pages. Thus we read
|
||||
** and submit data until we get our two packets, watching that no
|
||||
** pages are missing. If a page is missing, error out ; losing a
|
||||
** header page is the only place where missing data is fatal.
|
||||
*/
|
||||
@ -231,7 +233,7 @@ vorbis_read_header (SF_PRIVATE *psf)
|
||||
psf->dataoffset = ogg_sync_ftell (psf) ;
|
||||
|
||||
/*
|
||||
** Caculate the granule position offset. The first page with a payload
|
||||
** Calculate the granule position offset. The first page with a payload
|
||||
** packet shouldn't end in a continued packet. The difference between the
|
||||
** page's granule position and the sum of frames on the page tells us the
|
||||
** granule position offset.
|
||||
@ -240,7 +242,6 @@ vorbis_read_header (SF_PRIVATE *psf)
|
||||
ogg_stream_unpack_page (psf, odata) ;
|
||||
vdata->pcm_start = odata->pkt [odata->pkt_len - 1].granulepos ;
|
||||
duration = vorbis_calculate_page_duration (psf) ;
|
||||
|
||||
if (duration < (sf_count_t) vdata->pcm_start)
|
||||
vdata->pcm_start -= duration ;
|
||||
else
|
||||
@ -649,8 +650,8 @@ vorbis_read_sample (SF_PRIVATE *psf, void *ptr, sf_count_t lens, convert_func *t
|
||||
return i ;
|
||||
if (nn == 2)
|
||||
{ /* Ran over a hole. loc is now out of date, need to recalculate. */
|
||||
vdata->loc = odata->pkt [odata->pkt_len - 1].granulepos ;
|
||||
vdata->loc -= vorbis_calculate_page_duration (psf) ;
|
||||
vdata->loc = odata->pkt [odata->pkt_len - 1].granulepos -
|
||||
vorbis_calculate_page_duration (psf) ;
|
||||
}
|
||||
} ;
|
||||
|
||||
@ -791,11 +792,130 @@ vorbis_write_d (SF_PRIVATE *psf, const double *ptr, sf_count_t lens)
|
||||
return lens ;
|
||||
} /* vorbis_write_d */
|
||||
|
||||
static int
|
||||
vorbis_skip (SF_PRIVATE *psf, uint64_t target)
|
||||
{ OGG_PRIVATE *odata = (OGG_PRIVATE *) psf->container_data ;
|
||||
VORBIS_PRIVATE *vdata = (VORBIS_PRIVATE *) psf->codec_data ;
|
||||
ogg_packet *pkt ;
|
||||
int thisblock, lastblock, nn ;
|
||||
const int blocksize = vorbis_info_blocksize (&vdata->vinfo, 1) ;
|
||||
|
||||
/* Read out any samples in the decoder if any. */
|
||||
thisblock = vorbis_synthesis_pcmout (&vdata->vdsp, NULL) ;
|
||||
if (thisblock > 0)
|
||||
{ if ((uint64_t) thisblock + vdata->loc >= target)
|
||||
thisblock = SF_MIN (thisblock, (int) (target - vdata->loc)) ;
|
||||
|
||||
vorbis_synthesis_read (&vdata->vdsp, thisblock) ;
|
||||
vdata->loc += thisblock ;
|
||||
if (vdata->loc == target)
|
||||
return 0 ;
|
||||
} ;
|
||||
|
||||
lastblock = 0 ;
|
||||
for ( ; vdata->loc < target ; )
|
||||
{ /* Ensure there are unpacked packets. */
|
||||
if (odata->pkt_indx == odata->pkt_len)
|
||||
{ /* Page out of packets, load and unpack the next page. */
|
||||
nn = ogg_stream_unpack_page (psf, odata) ;
|
||||
if (nn < 0)
|
||||
return nn ;
|
||||
if (nn == 0)
|
||||
break ;
|
||||
if (nn == 2)
|
||||
{ /* Ran over a hole. loc is now out of date, need to recalculate. */
|
||||
vdata->loc = odata->pkt [odata->pkt_len - 1].granulepos -
|
||||
vorbis_calculate_page_duration (psf) ;
|
||||
}
|
||||
|
||||
if (target < vdata->loc)
|
||||
{ /* Our target is inside the hole :-( */
|
||||
return 0 ;
|
||||
} ;
|
||||
} ;
|
||||
|
||||
pkt = &odata->pkt [odata->pkt_indx] ;
|
||||
thisblock = vorbis_packet_blocksize (&vdata->vinfo, pkt) ;
|
||||
if (thisblock < 0)
|
||||
{ /* Not an audio packet */
|
||||
odata->pkt_indx++ ;
|
||||
continue ;
|
||||
} ;
|
||||
|
||||
if (lastblock)
|
||||
{ vdata->loc += ((lastblock + thisblock) / 4) ;
|
||||
} ;
|
||||
|
||||
/* Check to see if the block contains our target */
|
||||
if (vdata->loc + ((thisblock + blocksize) / 4) >= target)
|
||||
break ;
|
||||
|
||||
/* Block is before the target. Track for state, but don't decode. */
|
||||
odata->pkt_indx++ ;
|
||||
vorbis_synthesis_trackonly (&vdata->vblock, pkt) ;
|
||||
vorbis_synthesis_blockin (&vdata->vdsp, &vdata->vblock) ;
|
||||
lastblock = thisblock ;
|
||||
} ;
|
||||
|
||||
/* We are at the correct block, but still need to consume samples to reach
|
||||
** our target. */
|
||||
vorbis_read_sample (psf, (void *) NULL, (target - vdata->loc) * psf->sf.channels, vorbis_rnull) ;
|
||||
|
||||
return 0 ;
|
||||
} /* vorbis_skip */
|
||||
|
||||
static int
|
||||
vorbis_seek_trysearch (SF_PRIVATE *psf, uint64_t target_gp)
|
||||
{ OGG_PRIVATE *odata = (OGG_PRIVATE *) psf->container_data ;
|
||||
VORBIS_PRIVATE *vdata = (VORBIS_PRIVATE *) psf->codec_data ;
|
||||
uint64_t best_gp, search_target_gp ;
|
||||
int ret ;
|
||||
|
||||
/* Can't bisect a file we don't know the end of (cannot seek). */
|
||||
if (vdata->pcm_end == (uint64_t) -1)
|
||||
return 0 ;
|
||||
|
||||
/* If the target is for the near future, don't bother bisecting, just skip
|
||||
** to it. */
|
||||
if (target_gp >= vdata->loc &&
|
||||
target_gp - vdata->loc < ((unsigned) (VORBIS_SEEK_THRESHOLD) * psf->sf.samplerate))
|
||||
return 0 ;
|
||||
|
||||
/* Search for a position a half large-block before our target. As Vorbis is
|
||||
** lapped, every sample position come from two blocks, the "left" half of
|
||||
** one block and the "right" half of the previous block. The granule
|
||||
** position of an Ogg page of a Vorbis stream is the sample offset of the
|
||||
** last finished sample in the stream that can be decoded from a page. A
|
||||
** page also contains another half-block of samples waiting to be lapped
|
||||
** with the first half-block of samples from the next page.
|
||||
**
|
||||
** Searching for a sample one half of a large block before our target
|
||||
** guarantees we always load a page containing the previous half block
|
||||
** required to decode the target. Downside is we can't use best_gp
|
||||
** parameter of the page seek function. */
|
||||
search_target_gp = vorbis_info_blocksize (&vdata->vinfo, 1) / 2 ;
|
||||
search_target_gp = search_target_gp < target_gp ? target_gp - search_target_gp : 0 ;
|
||||
|
||||
ret = ogg_stream_seek_page_search (psf, odata, search_target_gp, vdata->pcm_start,
|
||||
vdata->pcm_end, &best_gp, psf->dataoffset, vdata->last_page) ;
|
||||
if (ret >= 0)
|
||||
{ ret = ogg_stream_unpack_page (psf, odata) ;
|
||||
if (ret == 1)
|
||||
{ /* Recalculate our granule position */
|
||||
vdata->loc = odata->pkt [odata->pkt_len - 1].granulepos -
|
||||
vorbis_calculate_page_duration (psf) ;
|
||||
vorbis_synthesis_restart (&vdata->vdsp) ;
|
||||
} ;
|
||||
} ;
|
||||
|
||||
return ret ;
|
||||
} /* vorbis_seek_trysearch */
|
||||
|
||||
static sf_count_t
|
||||
vorbis_seek (SF_PRIVATE *psf, int UNUSED (mode), sf_count_t offset)
|
||||
{ OGG_PRIVATE *odata = (OGG_PRIVATE *) psf->container_data ;
|
||||
VORBIS_PRIVATE *vdata = (VORBIS_PRIVATE *) psf->codec_data ;
|
||||
sf_count_t target ;
|
||||
uint64_t target_gp ;
|
||||
int ret ;
|
||||
|
||||
if (odata == NULL || vdata == NULL)
|
||||
@ -807,63 +927,29 @@ vorbis_seek (SF_PRIVATE *psf, int UNUSED (mode), sf_count_t offset)
|
||||
} ;
|
||||
|
||||
if (psf->file.mode == SFM_READ)
|
||||
{ target = offset + vdata->pcm_start ;
|
||||
{ target_gp = (uint64_t) offset + vdata->pcm_start ;
|
||||
ret = vorbis_seek_trysearch (psf, target_gp) ;
|
||||
|
||||
/*
|
||||
** If the end of the file is know, and the seek isn't for the near
|
||||
** future, do a search of the file for a good place to start.
|
||||
*/
|
||||
ret = 0 ;
|
||||
if ((vdata->pcm_end != (uint64_t) -1) &&
|
||||
(target < vdata->loc || target - vdata->loc > (2 * psf->sf.samplerate)))
|
||||
{ uint64_t best_gp ;
|
||||
|
||||
best_gp = vdata->pcm_start ;
|
||||
|
||||
ret = ogg_stream_seek_page_search (psf, odata, target, vdata->pcm_start,
|
||||
vdata->pcm_end, &best_gp, psf->dataoffset, vdata->last_page) ;
|
||||
if (ret >= 0)
|
||||
{ ret = ogg_stream_unpack_page (psf, odata) ;
|
||||
if (ret == 1)
|
||||
{ vdata->loc = best_gp ;
|
||||
vorbis_synthesis_restart (&vdata->vdsp) ;
|
||||
} ;
|
||||
} ;
|
||||
} ;
|
||||
|
||||
if (ret >= 0 && offset + (sf_count_t) vdata->pcm_start >= vdata->loc)
|
||||
target = offset + vdata->pcm_start - vdata->loc ;
|
||||
else
|
||||
if (ret < 0 || vdata->loc > target_gp)
|
||||
{ /* Search failed (bad data?), reset to the beginning of the stream. */
|
||||
psf_log_printf (psf, "Seek search failed. Reading through stream from start.\n") ;
|
||||
ogg_stream_reset_serialno (&odata->ostream, odata->ostream.serialno) ;
|
||||
odata->pkt_len = 0 ;
|
||||
odata->pkt_indx = 0 ;
|
||||
ogg_sync_fseek (psf, psf->dataoffset, SEEK_SET) ;
|
||||
vdata->loc = 0 ;
|
||||
vorbis_synthesis_restart (&vdata->vdsp) ;
|
||||
target = offset ;
|
||||
} ;
|
||||
|
||||
while (target > 0)
|
||||
{ sf_count_t m = target > 4096 ? 4096 : target ;
|
||||
|
||||
/*
|
||||
** Need to multiply by channels here because the seek is done in
|
||||
** terms of frames and the read function is done in terms of
|
||||
** samples.
|
||||
*/
|
||||
vorbis_read_sample (psf, (void *) NULL, m * psf->sf.channels, vorbis_rnull) ;
|
||||
|
||||
target -= m ;
|
||||
} ;
|
||||
vorbis_skip (psf, target_gp) ;
|
||||
|
||||
return vdata->loc - vdata->pcm_start ;
|
||||
} ;
|
||||
|
||||
return 0 ;
|
||||
psf->error = SFE_BAD_SEEK ;
|
||||
return ((sf_count_t) -1) ;
|
||||
} /* vorbis_seek */
|
||||
|
||||
|
||||
static int
|
||||
vorbis_byterate (SF_PRIVATE *psf)
|
||||
{
|
||||
@ -877,9 +963,13 @@ static sf_count_t
|
||||
vorbis_calculate_page_duration (SF_PRIVATE *psf)
|
||||
{ OGG_PRIVATE *odata = (OGG_PRIVATE *) psf->container_data ;
|
||||
VORBIS_PRIVATE *vdata = (VORBIS_PRIVATE *) psf->codec_data ;
|
||||
long thisblock, lastblock ;
|
||||
int thisblock, lastblock, i ;
|
||||
sf_count_t duration ;
|
||||
int i ;
|
||||
|
||||
/*
|
||||
** Calculate how many samples can be decoded from blocks in this page,
|
||||
** accounting for the fact that blocks are 1/2 lapped.
|
||||
*/
|
||||
|
||||
lastblock = -1 ;
|
||||
duration = 0 ;
|
||||
@ -893,7 +983,7 @@ vorbis_calculate_page_duration (SF_PRIVATE *psf)
|
||||
} ;
|
||||
|
||||
return duration ;
|
||||
}
|
||||
} /* vorbis_calculate_page_duration */
|
||||
|
||||
#else /* HAVE_EXTERNAL_XIPH_LIBS */
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user