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rockbox/apps/plugins/mpegplayer/mpeg_parser.c
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or 
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

1210 lines
36 KiB
C
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Parser for MPEG streams
*
* Copyright (c) 2007 Michael Sevakis
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "plugin.h"
#include "mpegplayer.h"
struct stream_parser str_parser SHAREDBSS_ATTR;
static void parser_init_state(void)
{
str_parser.last_seek_time = 0;
str_parser.format = STREAM_FMT_UNKNOWN;
str_parser.start_pts = INVALID_TIMESTAMP;
str_parser.end_pts = INVALID_TIMESTAMP;
str_parser.flags = 0;
str_parser.dims.w = 0;
str_parser.dims.h = 0;
}
/* Place the stream in a state to begin parsing - sync will be performed
* first */
void str_initialize(struct stream *str, off_t pos)
{
/* Initial positions start here */
str->hdr.win_left = str->hdr.win_right = pos;
/* No packet */
str->curr_packet = NULL;
/* Pick up parsing from this point in the buffer */
str->curr_packet_end = disk_buf_offset2ptr(pos);
/* No flags */
str->pkt_flags = 0;
/* Sync first */
str->state = SSTATE_SYNC;
}
/* Place the stream in an end of data state */
void str_end_of_stream(struct stream *str)
{
/* Offsets that prevent this stream from being included in the
* min left/max right window so that no buffering is triggered on
* its behalf. Set right to the min first so a thread reading the
* overall window gets doesn't see this as valid no matter what the
* file length. */
str->hdr.win_right = LONG_MIN;
str->hdr.win_left = LONG_MAX;
/* No packets */
str->curr_packet = str->curr_packet_end = NULL;
/* No flags */
str->pkt_flags = 0;
/* Fin */
str->state = SSTATE_END;
}
/* Return a timestamp at address p+offset if the marker bits are in tact */
static inline uint32_t read_pts(uint8_t *p, off_t offset)
{
return TS_CHECK_MARKERS(p, offset) ?
TS_FROM_HEADER(p, offset) : INVALID_TIMESTAMP;
}
static inline bool validate_timestamp(uint32_t ts)
{
return ts >= str_parser.start_pts && ts <= str_parser.end_pts;
}
/* Find a start code before or after a given position */
uint8_t * mpeg_parser_scan_start_code(struct stream_scan *sk, uint32_t code)
{
stream_scan_normalize(sk);
if (sk->dir < 0)
{
/* Reverse scan - start with at least the min needed */
stream_scan_offset(sk, 4);
}
code &= 0xff; /* Only the low byte matters */
while (sk->len >= 0 && sk->margin >= 4)
{
uint8_t *p;
off_t pos = disk_buf_lseek(sk->pos, SEEK_SET);
ssize_t len = disk_buf_getbuffer(4, &p, NULL, NULL);
if (pos < 0 || len < 4)
break;
if (CMP_3_CONST(p, PACKET_START_CODE_PREFIX) && p[3] == code)
{
return p;
}
stream_scan_offset(sk, 1);
}
return NULL;
}
/* Find a PES packet header for any stream - return stream to which it
* belongs */
unsigned mpeg_parser_scan_pes(struct stream_scan *sk)
{
stream_scan_normalize(sk);
if (sk->dir < 0)
{
/* Reverse scan - start with at least the min needed */
stream_scan_offset(sk, 4);
}
while (sk->len >= 0 && sk->margin >= 4)
{
uint8_t *p;
off_t pos = disk_buf_lseek(sk->pos, SEEK_SET);
ssize_t len = disk_buf_getbuffer(4, &p, NULL, NULL);
if (pos < 0 || len < 4)
break;
if (CMP_3_CONST(p, PACKET_START_CODE_PREFIX))
{
unsigned id = p[3];
if (id >= 0xb9)
return id; /* PES header */
/* else some video stream element */
}
stream_scan_offset(sk, 1);
}
return -1;
}
/* Return the first SCR found from the scan direction */
uint32_t mpeg_parser_scan_scr(struct stream_scan *sk)
{
uint8_t *p = mpeg_parser_scan_start_code(sk, MPEG_STREAM_PACK_HEADER);
if (p != NULL && sk->margin >= 9) /* 9 bytes total required */
{
sk->data = 9;
if ((p[4] & 0xc0) == 0x40) /* mpeg-2 */
{
/* Lookhead p+8 */
if (MPEG2_CHECK_PACK_SCR_MARKERS(p, 4))
return MPEG2_PACK_HEADER_SCR(p, 4);
}
else if ((p[4] & 0xf0) == 0x20) /* mpeg-1 */
{
/* Lookahead p+8 */
if (TS_CHECK_MARKERS(p, 4))
return TS_FROM_HEADER(p, 4);
}
/* Weird pack header */
sk->data = 5;
}
return INVALID_TIMESTAMP;
}
uint32_t mpeg_parser_scan_pts(struct stream_scan *sk, unsigned id)
{
stream_scan_normalize(sk);
if (sk->dir < 0)
{
/* Reverse scan - start with at least the min needed */
stream_scan_offset(sk, 4);
}
while (sk->len >= 0 && sk->margin >= 4)
{
uint8_t *p;
off_t pos = disk_buf_lseek(sk->pos, SEEK_SET);
ssize_t len = disk_buf_getbuffer(35, &p, NULL, NULL);
if (pos < 0 || len < 4)
break;
if (CMP_3_CONST(p, PACKET_START_CODE_PREFIX) && p[3] == id)
{
uint8_t *h = p;
if (sk->margin < 6)
{
/* Insufficient data */
}
else if ((h[6] & 0xc0) == 0x80) /* mpeg2 */
{
if (sk->margin >= 14 && (h[7] & 0x80) != 0x00)
{
sk->data = 14;
return read_pts(h, 9);
}
}
else /* mpeg1 */
{
ssize_t l = 7;
ssize_t margin = sk->margin;
/* Skip stuffing_byte */
while (h[l - 1] == 0xff && ++l <= 23)
--margin;
if ((h[l - 1] & 0xc0) == 0x40)
{
/* Skip STD_buffer_scale and STD_buffer_size */
margin -= 2;
l += 2;
}
if (margin >= 4)
{
/* header points to the mpeg1 pes header */
h += l;
if ((h[-1] & 0xe0) == 0x20)
{
sk->data = (h + 4) - p;
return read_pts(h, -1);
}
}
}
/* No PTS present - keep searching for a matching PES header with
* one */
}
stream_scan_offset(sk, 1);
}
return INVALID_TIMESTAMP;
}
static bool init_video_info(void)
{
DEBUGF("Getting movie size\n");
/* The decoder handles this in order to initialize its knowledge of the
* movie parameters making seeking easier */
str_send_msg(&video_str, STREAM_RESET, 0);
if (str_send_msg(&video_str, VIDEO_GET_SIZE,
(intptr_t)&str_parser.dims) != 0)
{
return true;
}
DEBUGF(" failed\n");
return false;
}
static void init_times(struct stream *str)
{
int i;
struct stream tmp_str;
const ssize_t filesize = disk_buf_filesize();
const ssize_t max_probe = MIN(512*1024, filesize);
/* Simply find the first earliest timestamp - this will be the one
* used when streaming anyway */
DEBUGF("Finding start_pts: 0x%02x\n", str->id);
tmp_str.id = str->id;
tmp_str.hdr.pos = 0;
tmp_str.hdr.limit = max_probe;
str->start_pts = INVALID_TIMESTAMP;
/* Probe many for video because of B-frames */
for (i = STREAM_IS_VIDEO(str->id) ? 5 : 1; i > 0;)
{
switch (parser_get_next_data(&tmp_str, STREAM_PM_RANDOM_ACCESS))
{
case STREAM_DATA_END:
break;
case STREAM_OK:
if (tmp_str.pkt_flags & PKT_HAS_TS)
{
if (tmp_str.pts < str->start_pts)
str->start_pts = tmp_str.pts;
i--; /* Decrement timestamp counter */
}
continue;
}
break;
}
DEBUGF(" start:%u\n", (unsigned)str->start_pts);
/* Use the decoder thread to perform a synchronized search - no
* decoding should take place but just a simple run through timestamps
* and durations as the decoder would see them. This should give the
* precise time at the end of the last frame for the stream. */
DEBUGF("Finding end_pts: 0x%02x\n", str->id);
str->end_pts = INVALID_TIMESTAMP;
if (str->start_pts != INVALID_TIMESTAMP)
{
str_parser.parms.sd.time = MAX_TIMESTAMP;
str_parser.parms.sd.sk.pos = filesize - max_probe;
str_parser.parms.sd.sk.len = max_probe;
str_parser.parms.sd.sk.dir = SSCAN_FORWARD;
str_send_msg(str, STREAM_RESET, 0);
if (str_send_msg(str, STREAM_FIND_END_TIME,
(intptr_t)&str_parser.parms.sd) == STREAM_PERFECT_MATCH)
{
str->end_pts = str_parser.parms.sd.time;
DEBUGF(" end:%u\n", (unsigned)str->end_pts);
}
}
/* End must be greater than start */
if (str->start_pts >= str->end_pts)
{
str->start_pts = INVALID_TIMESTAMP;
str->end_pts = INVALID_TIMESTAMP;
}
}
/* Return the best-fit file offset of a timestamp in the PES where
* timstamp <= time < next timestamp. Will try to return something reasonably
* valid if best-fit could not be made. */
static off_t mpeg_parser_seek_PTS(uint32_t time, unsigned id)
{
ssize_t pos_left = 0;
ssize_t pos_right = disk_buf.filesize;
ssize_t pos, pos_new;
uint32_t time_left = str_parser.start_pts;
uint32_t time_right = str_parser.end_pts;
uint32_t pts = 0;
uint32_t prevpts = 0;
enum state_enum state = state0;
struct stream_scan sk;
/* Initial estimate taken from average bitrate - later interpolations are
* taken similarly based on the remaining file interval */
pos_new = muldiv_uint32(time - time_left, pos_right - pos_left,
time_right - time_left) + pos_left;
/* return this estimated position if nothing better comes up */
pos = pos_new;
DEBUGF("Seeking stream 0x%02x\n", id);
DEBUGF("$$ tl:%u t:%u ct:?? tr:%u\n pl:%ld pn:%ld pr:%ld\n",
(unsigned)time_left, (unsigned)time, (unsigned)time_right,
pos_left, pos_new, pos_right);
sk.dir = SSCAN_REVERSE;
while (state < state9)
{
uint32_t currpts;
sk.pos = pos_new;
sk.len = (sk.dir < 0) ? pos_new - pos_left : pos_right - pos_new;
currpts = mpeg_parser_scan_pts(&sk, id);
if (currpts != INVALID_TIMESTAMP)
{
ssize_t pos_adj; /* Adjustment to over or under-estimate */
/* Found a valid timestamp - see were it lies in relation to
* target */
if (currpts < time)
{
/* Time at current position is before seek time - move
* forward */
if (currpts > pts)
{
/* This is less than the desired time but greater than
* the currently seeked one; move the position up */
pts = currpts;
pos = sk.pos;
}
/* No next timestamp can be sooner */
pos_left = sk.pos + sk.data;
time_left = currpts;
if (pos_right <= pos_left)
break; /* If the window disappeared - we're done */
pos_new = muldiv_uint32(time - time_left,
pos_right - pos_left,
time_right - time_left);
/* Point is ahead of us - fudge estimate a bit high */
pos_adj = pos_new / 10;
if (pos_adj > 512*1024)
pos_adj = 512*1024;
pos_new += pos_left + pos_adj;
if (pos_new >= pos_right)
{
/* Estimate could push too far */
pos_new = pos_right;
}
state = state2; /* Last scan was early */
sk.dir = SSCAN_REVERSE;
DEBUGF(">> tl:%u t:%u ct:%u tr:%u\n pl:%ld pn:%ld pr:%ld\n",
(unsigned)time_left, (unsigned)time, (unsigned)currpts,
(unsigned)time_right, pos_left, pos_new, pos_right);
}
else if (currpts > time)
{
/* Time at current position is past seek time - move
backward */
pos_right = sk.pos;
time_right = currpts;
if (pos_right <= pos_left)
break; /* If the window disappeared - we're done */
pos_new = muldiv_uint32(time - time_left,
pos_right - pos_left,
time_right - time_left);
/* Overshot the seek point - fudge estimate a bit low */
pos_adj = pos_new / 10;
if (pos_adj > 512*1024)
pos_adj = 512*1024;
pos_new += pos_left - pos_adj;
state = state3; /* Last scan was late */
sk.dir = SSCAN_REVERSE;
DEBUGF("<< tl:%u t:%u ct:%u tr:%u\n pl:%ld pn:%ld pr:%ld\n",
(unsigned)time_left, (unsigned)time, (unsigned)currpts,
(unsigned)time_right, pos_left, pos_new, pos_right);
}
else
{
/* Exact match - it happens */
DEBUGF("|| tl:%u t:%u ct:%u tr:%u\n pl:%ld pn:%ld pr:%ld\n",
(unsigned)time_left, (unsigned)time, (unsigned)currpts,
(unsigned)time_right, pos_left, pos_new, pos_right);
pts = currpts;
pos = sk.pos;
state = state9;
}
}
else
{
/* Nothing found */
switch (state)
{
case state1:
/* We already tried the bruteforce scan and failed again - no
* more stamps could possibly exist in the interval */
DEBUGF("!! no timestamp 2x\n");
break;
case state0:
/* Hardly likely except at very beginning - just do L->R scan
* to find something */
DEBUGF("!! no timestamp on first probe: %ld\n", sk.pos);
case state2:
case state3:
/* Could just be missing timestamps because the interval is
* narrowing down. A large block of data from another stream
* may also be in the midst of our chosen points which could
* cluster at either extreme end. If anything is there, this
* will find it. */
pos_new = pos_left;
sk.dir = SSCAN_FORWARD;
DEBUGF("?? tl:%u t:%u ct:%u tr:%u\n pl:%ld pn:%ld pr:%ld\n",
(unsigned)time_left, (unsigned)time, (unsigned)currpts,
(unsigned)time_right, pos_left, pos_new, pos_right);
state = state1;
break;
default:
DEBUGF("?? Invalid state: %d\n", state);
}
}
/* Same timestamp twice = quit */
if (currpts == prevpts)
{
DEBUGF("!! currpts == prevpts (stop)\n");
state = state9;
}
prevpts = currpts;
}
#if defined(DEBUG) || defined(SIMULATOR)
/* The next pts after the seeked-to position should be greater -
* most of the time - frames out of presentation order may muck it
* up a slight bit */
sk.pos = pos + 1;
sk.len = disk_buf.filesize;
sk.dir = SSCAN_FORWARD;
uint32_t nextpts = mpeg_parser_scan_pts(&sk, id);
DEBUGF("Seek pos:%ld pts:%u t:%u next pts:%u \n",
pos, (unsigned)pts, (unsigned)time, (unsigned)nextpts);
if (pts <= time && time < nextpts)
{
/* Smile - it worked */
DEBUGF(" :) pts<=time<next pts\n");
}
else
{
/* See where things ended up */
if (pts > time)
{
/* Hmm */
DEBUGF(" :\\ pts>time\n");
}
if (pts >= nextpts)
{
/* Weird - probably because of encoded order & tends to be right
* anyway if other criteria are met */
DEBUGF(" :p pts>=next pts\n");
}
if (time >= nextpts)
{
/* Ugh */
DEBUGF(" :( time>=nextpts\n");
}
}
#endif
return pos;
}
static bool prepare_image(uint32_t time)
{
struct stream_scan sk;
int tries;
int result;
if (!str_send_msg(&video_str, STREAM_NEEDS_SYNC, time))
{
DEBUGF("Image was ready\n");
return true; /* Should already have the image */
}
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
rb->cpu_boost(true); /* No interference with trigger_cpu_boost */
#endif
str_send_msg(&video_str, STREAM_RESET, 0);
sk.pos = parser_can_seek() ?
mpeg_parser_seek_PTS(time, video_str.id) : 0;
sk.len = sk.pos;
sk.dir = SSCAN_REVERSE;
tries = 1;
try_again:
if (mpeg_parser_scan_start_code(&sk, MPEG_START_GOP))
{
DEBUGF("GOP found at: %ld\n", sk.pos);
unsigned id = mpeg_parser_scan_pes(&sk);
if (id != video_str.id && sk.pos > 0)
{
/* Not part of our stream */
DEBUGF(" wrong stream: 0x%02x\n", id);
goto try_again;
}
/* This will hit the PES header since it's known to be there */
uint32_t pts = mpeg_parser_scan_pts(&sk, id);
if (pts == INVALID_TIMESTAMP || pts > time)
{
DEBUGF(" wrong timestamp: %u\n", (unsigned)pts);
goto try_again;
}
}
str_parser.parms.sd.time = time;
str_parser.parms.sd.sk.pos = MAX(sk.pos, 0);
str_parser.parms.sd.sk.len = 1024*1024;
str_parser.parms.sd.sk.dir = SSCAN_FORWARD;
DEBUGF("thumb pos:%ld len:%ld\n", str_parser.parms.sd.sk.pos,
str_parser.parms.sd.sk.len);
result = str_send_msg(&video_str, STREAM_SYNC,
(intptr_t)&str_parser.parms.sd);
if (result != STREAM_PERFECT_MATCH)
{
/* Two tries should be all that is nescessary to find the exact frame
* if the first GOP actually started later than the timestamp - the
* GOP just prior must then start on or earlier. */
if (++tries <= 2)
goto try_again;
}
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
rb->cpu_boost(false);
#endif
return result > STREAM_OK;
}
static void prepare_audio(uint32_t time)
{
off_t pos;
if (!str_send_msg(&audio_str, STREAM_NEEDS_SYNC, time))
{
DEBUGF("Audio was ready\n");
return;
}
pos = mpeg_parser_seek_PTS(time, audio_str.id);
str_send_msg(&audio_str, STREAM_RESET, 0);
str_parser.parms.sd.time = time;
str_parser.parms.sd.sk.pos = pos;
str_parser.parms.sd.sk.len = 1024*1024;
str_parser.parms.sd.sk.dir = SSCAN_FORWARD;
str_send_msg(&audio_str, STREAM_SYNC, (intptr_t)&str_parser.parms.sd);
}
/* This function demuxes the streams and gives the next stream data
* pointer.
*
* STREAM_PM_STREAMING is for operation during playback. If the nescessary
* data and worst-case lookahead margin is not available, the stream is
* registered for notification when the data becomes available. If parsing
* extends beyond the end of the file or the end of stream marker is reached,
* STREAM_DATA_END is returned and the stream state changed to SSTATE_EOS.
*
* STREAM_PM_RANDOM_ACCESS is for operation when not playing such as seeking.
* If the file cache misses for the current position + lookahead, it will be
* loaded from disk. When the specified limit is reached, STREAM_DATA_END is
* returned.
*
* The results from one mode may be used as input to the other. Random access
* requires cooperation amongst threads to avoid evicting another stream's
* data.
*/
static int parse_demux(struct stream *str, enum stream_parse_mode type)
{
#define INC_BUF(offset) \
({ off_t _o = (offset); \
str->hdr.win_right += _o; \
if ((p += _o) >= disk_buf.end) \
p -= disk_buf.size; })
static const int mpeg1_skip_table[16] =
{ 0, 0, 4, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
uint8_t *p = str->curr_packet_end;
str->pkt_flags = 0;
while (1)
{
uint8_t *header;
unsigned id;
ssize_t length, bytes;
switch (type)
{
case STREAM_PM_STREAMING:
/* Has the end been reached already? */
switch (str->state)
{
case SSTATE_PARSE: /* Expected case first if no jumptable */
/* Are we at the end of file? */
if (str->hdr.win_left < disk_buf.filesize)
break;
str_end_of_stream(str);
return STREAM_DATA_END;
case SSTATE_SYNC:
/* Is sync at the end of file? */
if (str->hdr.win_right < disk_buf.filesize)
break;
str_end_of_stream(str);
/* Fall-through */
case SSTATE_END:
return STREAM_DATA_END;
}
if (!disk_buf_is_data_ready(&str->hdr, MIN_BUFAHEAD))
{
/* This data range is not buffered yet - register stream to
* be notified when it becomes available. Stream is obliged
* to enter a TSTATE_DATA state if it must wait. */
int res = str_next_data_not_ready(str);
if (res != STREAM_OK)
return res;
}
break;
/* STREAM_PM_STREAMING: */
case STREAM_PM_RANDOM_ACCESS:
str->hdr.pos = disk_buf_lseek(str->hdr.pos, SEEK_SET);
if (str->hdr.pos < 0 || str->hdr.pos >= str->hdr.limit ||
disk_buf_getbuffer(MIN_BUFAHEAD, &p, NULL, NULL) <= 0)
{
str_end_of_stream(str);
return STREAM_DATA_END;
}
str->state = SSTATE_SYNC;
str->hdr.win_left = str->hdr.pos;
str->curr_packet = NULL;
str->curr_packet_end = p;
break;
/* STREAM_PM_RANDOM_ACCESS: */
}
if (str->state == SSTATE_SYNC)
{
/* Scanning for start code */
if (!CMP_3_CONST(p, PACKET_START_CODE_PREFIX))
{
INC_BUF(1);
continue;
}
}
/* Found a start code - enter parse state */
str->state = SSTATE_PARSE;
/* Pack header, skip it */
if (CMP_4_CONST(p, PACK_START_CODE))
{
/* Max lookahead: 14 */
if ((p[4] & 0xc0) == 0x40) /* mpeg-2 */
{
/* Max delta: 14 + 7 = 21 */
/* Skip pack header and any stuffing bytes*/
bytes = 14 + (p[13] & 7);
}
else if ((p[4] & 0xf0) == 0x20) /* mpeg-1 */
{
bytes = 12;
}
else /* unknown - skip it */
{
DEBUGF("weird pack header!\n");
bytes = 5;
}
INC_BUF(bytes);
}
/* System header, parse and skip it - 6 bytes + size */
if (CMP_4_CONST(p, SYSTEM_HEADER_START_CODE))
{
/* Skip start code */
/* Max Delta = 65535 + 6 = 65541 */
bytes = 6 + ((p[4] << 8) | p[5]);
INC_BUF(bytes);
}
/* Packet header, parse it */
if (!CMP_3_CONST(p, PACKET_START_CODE_PREFIX))
{
/* Problem? Meh...probably not but just a corrupted section.
* Try to resync the parser which will probably succeed. */
DEBUGF("packet start code prefix not found: 0x%02x\n"
" wl:%lu wr:%lu\n"
" p:%p cp:%p cpe:%p\n"
" dbs:%p dbe:%p dbt:%p\n",
str->id, str->hdr.win_left, str->hdr.win_right,
p, str->curr_packet, str->curr_packet_end,
disk_buf.start, disk_buf.end, disk_buf.tail);
str->state = SSTATE_SYNC;
INC_BUF(1); /* Next byte - this one's no good */
continue;
}
/* We retrieve basic infos */
/* Maximum packet length: 6 + 65535 = 65541 */
id = p[3];
length = ((p[4] << 8) | p[5]) + 6;
if (id != str->id)
{
switch (id)
{
case MPEG_STREAM_PROGRAM_END:
/* end of stream */
str_end_of_stream(str);
DEBUGF("MPEG program end: 0x%02x\n", str->id);
return STREAM_DATA_END;
case MPEG_STREAM_PACK_HEADER:
case MPEG_STREAM_SYSTEM_HEADER:
/* These shouldn't be here - no increment or resync
* since we'll pick it up above. */
continue;
default:
/* It's not the packet we're looking for, skip it */
INC_BUF(length);
continue;
}
}
/* Ok, it's our packet */
header = p;
if ((header[6] & 0xc0) == 0x80) /* mpeg2 */
{
/* Max Lookahead: 18 */
/* Min length: 9 */
/* Max length: 9 + 255 = 264 */
length = 9 + header[8];
/* header points to the mpeg2 pes header */
if ((header[7] & 0x80) != 0)
{
/* header has a pts */
uint32_t pts = read_pts(header, 9);
if (pts != INVALID_TIMESTAMP)
{
str->pts = pts;
#if 0
/* DTS isn't used for anything since things just get
decoded ASAP but keep the code around */
if (STREAM_IS_VIDEO(id))
{
/* Video stream - header may have a dts as well */
str->dts = pts;
if (header[7] & 0x40) != 0x00)
{
pts = read_pts(header, 14);
if (pts != INVALID_TIMESTAMP)
str->dts = pts;
}
}
#endif
str->pkt_flags |= PKT_HAS_TS;
}
}
}
else /* mpeg1 */
{
/* Max lookahead: 24 + 2 + 9 = 35 */
/* Max len_skip: 24 + 2 = 26 */
/* Min length: 7 */
/* Max length: 24 + 2 + 9 = 35 */
off_t len_skip;
uint8_t * ptsbuf;
length = 7;
while (header[length - 1] == 0xff)
{
if (++length > 23)
{
DEBUGF("Too much stuffing" );
break;
}
}
if ((header[length - 1] & 0xc0) == 0x40)
length += 2;
len_skip = length;
length += mpeg1_skip_table[header[length - 1] >> 4];
/* Header points to the mpeg1 pes header */
ptsbuf = header + len_skip;
if ((ptsbuf[-1] & 0xe0) == 0x20 && TS_CHECK_MARKERS(ptsbuf, -1))
{
/* header has a pts */
uint32_t pts = read_pts(ptsbuf, -1);
if (pts != INVALID_TIMESTAMP)
{
str->pts = pts;
#if 0
/* DTS isn't used for anything since things just get
decoded ASAP but keep the code around */
if (STREAM_IS_VIDEO(id))
{
/* Video stream - header may have a dts as well */
str->dts = pts;
if (ptsbuf[-1] & 0xf0) == 0x30)
{
pts = read_pts(ptsbuf, 4);
if (pts != INVALID_TIMESTAMP)
str->dts = pts;
}
}
#endif
str->pkt_flags |= PKT_HAS_TS;
}
}
}
p += length;
/* Max bytes: 6 + 65535 - 7 = 65534 */
bytes = 6 + (header[4] << 8) + header[5] - length;
str->curr_packet = p;
str->curr_packet_end = p + bytes;
str->hdr.win_left = str->hdr.win_right + length;
str->hdr.win_right = str->hdr.win_left + bytes;
if (str->hdr.win_right > disk_buf.filesize)
{
/* No packet that exceeds end of file can be valid */
str_end_of_stream(str);
return STREAM_DATA_END;
}
return STREAM_OK;
} /* end while */
#undef INC_BUF
}
/* This simply reads data from the file one page at a time and returns a
* pointer to it in the buffer. */
static int parse_elementary(struct stream *str, enum stream_parse_mode type)
{
uint8_t *p;
ssize_t len = 0;
str->pkt_flags = 0;
switch (type)
{
case STREAM_PM_STREAMING:
/* Has the end been reached already? */
if (str->state == SSTATE_END)
return STREAM_DATA_END;
/* Are we at the end of file? */
if (str->hdr.win_left >= disk_buf.filesize)
{
str_end_of_stream(str);
return STREAM_DATA_END;
}
if (!disk_buf_is_data_ready(&str->hdr, MIN_BUFAHEAD))
{
/* This data range is not buffered yet - register stream to
* be notified when it becomes available. Stream is obliged
* to enter a TSTATE_DATA state if it must wait. */
int res = str_next_data_not_ready(str);
if (res != STREAM_OK)
return res;
}
len = DISK_BUF_PAGE_SIZE;
if ((size_t)(str->hdr.win_right + len) > (size_t)disk_buf.filesize)
len = disk_buf.filesize - str->hdr.win_right;
if (len <= 0)
{
str_end_of_stream(str);
return STREAM_DATA_END;
}
p = str->curr_packet_end;
if (p >= disk_buf.end)
p -= disk_buf.size;
break;
/* STREAM_PM_STREAMING: */
case STREAM_PM_RANDOM_ACCESS:
str->hdr.pos = disk_buf_lseek(str->hdr.pos, SEEK_SET);
len = disk_buf_getbuffer(DISK_BUF_PAGE_SIZE, &p, NULL, NULL);
if (len <= 0 || str->hdr.pos < 0 || str->hdr.pos >= str->hdr.limit)
{
str_end_of_stream(str);
return STREAM_DATA_END;
}
break;
/* STREAM_PM_RANDOM_ACCESS: */
}
str->state = SSTATE_PARSE;
str->curr_packet = p;
str->curr_packet_end = p + len;
str->hdr.win_left = str->hdr.win_right;
str->hdr.win_right = str->hdr.win_left + len;
return STREAM_OK;
}
intptr_t parser_send_video_msg(long id, intptr_t data)
{
intptr_t retval = 0;
if (video_str.thread != NULL && disk_buf.in_file >= 0)
{
/* Hook certain messages since they involve multiple operations
* behind the scenes */
switch (id)
{
case VIDEO_DISPLAY_SHOW:
if (data != 0 && disk_buf_status() == STREAM_STOPPED)
{ /* Only prepare image if showing and not playing */
prepare_image(str_parser.last_seek_time);
}
break;
case VIDEO_PRINT_FRAME:
if (data)
break;
case VIDEO_PRINT_THUMBNAIL:
if (disk_buf_status() != STREAM_STOPPED)
break; /* Prepare image if not playing */
if (!prepare_image(str_parser.last_seek_time))
return false; /* Preparation failed */
/* Image ready - pass message to video thread */
break;
}
retval = str_send_msg(&video_str, id, data);
}
return retval;
}
/* Seek parser to the specified time and return absolute time.
* No actual hard stuff is performed here. That's done when streaming is
* about to begin or something from the current position is requested */
uint32_t parser_seek_time(uint32_t time)
{
if (!parser_can_seek())
time = 0;
else if (time > str_parser.duration)
time = str_parser.duration;
str_parser.last_seek_time = time + str_parser.start_pts;
return str_parser.last_seek_time;
}
void parser_prepare_streaming(void)
{
struct stream_window sw;
DEBUGF("parser_prepare_streaming\n");
/* Prepare initial video frame */
prepare_image(str_parser.last_seek_time);
/* Sync audio stream */
if (audio_str.start_pts != INVALID_TIMESTAMP)
prepare_audio(str_parser.last_seek_time);
/* Prequeue some data and set buffer window */
if (!stream_get_window(&sw))
sw.left = sw.right = disk_buf.filesize;
DEBUGF(" swl:%ld swr:%ld\n", sw.left, sw.right);
if (sw.right > disk_buf.filesize - 4*MIN_BUFAHEAD)
sw.right = disk_buf.filesize - 4*MIN_BUFAHEAD;
disk_buf_prepare_streaming(sw.left,
sw.right - sw.left + 4*MIN_BUFAHEAD);
}
int parser_init_stream(void)
{
if (disk_buf.in_file < 0)
return STREAM_ERROR;
/* TODO: Actually find which streams are available */
audio_str.id = MPEG_STREAM_AUDIO_FIRST;
video_str.id = MPEG_STREAM_VIDEO_FIRST;
/* Try to pull a video PES - if not found, try video init anyway which
* should succeed if it really is a video-only stream */
video_str.hdr.pos = 0;
video_str.hdr.limit = 256*1024;
if (parse_demux(&video_str, STREAM_PM_RANDOM_ACCESS) == STREAM_OK)
{
/* Found a video packet - assume transport stream */
str_parser.format = STREAM_FMT_MPEG_TS;
str_parser.next_data = parse_demux;
}
else
{
/* No PES element found - assume video elementary stream */
str_parser.format = STREAM_FMT_MPV;
str_parser.next_data = parse_elementary;
}
if (!init_video_info())
{
/* Cannot determine video size, etc. */
return STREAM_UNSUPPORTED;
}
if (str_parser.format == STREAM_FMT_MPEG_TS)
{
/* Initalize start_pts and end_pts with the length (in 45kHz units) of
* the movie. INVALID_TIMESTAMP if the time could not be determined */
init_times(&audio_str);
init_times(&video_str);
if (video_str.start_pts == INVALID_TIMESTAMP)
{
/* Must have video at least */
return STREAM_UNSUPPORTED;
}
str_parser.flags |= STREAMF_CAN_SEEK;
if (audio_str.start_pts != INVALID_TIMESTAMP)
{
/* Overall duration is maximum span */
str_parser.start_pts = MIN(audio_str.start_pts, video_str.start_pts);
str_parser.end_pts = MAX(audio_str.end_pts, video_str.end_pts);
/* Audio will be part of playback pool */
stream_add_stream(&audio_str);
}
else
{
/* No audio stream - use video only */
str_parser.start_pts = video_str.start_pts;
str_parser.end_pts = video_str.end_pts;
}
str_parser.last_seek_time = str_parser.start_pts;
}
else
{
/* There's no way to handle times on this without a full file
* scan */
audio_str.start_pts = INVALID_TIMESTAMP;
audio_str.end_pts = INVALID_TIMESTAMP;
video_str.start_pts = 0;
video_str.end_pts = INVALID_TIMESTAMP;
str_parser.start_pts = 0;
str_parser.end_pts = INVALID_TIMESTAMP;
}
/* Add video to playback pool */
stream_add_stream(&video_str);
/* Cache duration - it's used very often */
str_parser.duration = str_parser.end_pts - str_parser.start_pts;
DEBUGF("Movie info:\n"
" size:%dx%d\n"
" start:%u\n"
" end:%u\n"
" duration:%u\n",
str_parser.dims.w, str_parser.dims.h,
(unsigned)str_parser.start_pts,
(unsigned)str_parser.end_pts,
(unsigned)str_parser.duration);
return STREAM_OK;
}
void parser_close_stream(void)
{
stream_remove_streams();
parser_init_state();
}
bool parser_init(void)
{
parser_init_state();
return true;
}
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