static size_t cx18_copy_buf_to_user(struct cx18_stream *s,
struct cx18_buffer *buf, char __user *ubuf, size_t ucount)
{
struct cx18 *cx = s->cx;
size_t len = buf->bytesused - buf->readpos;
if (len > ucount)
len = ucount;
if (cx->vbi.insert_mpeg && s->type == CX18_ENC_STREAM_TYPE_MPG &&
cx->vbi.sliced_in->service_set && buf != &cx->vbi.sliced_mpeg_buf) {
const char *start = buf->buf + buf->readpos;
const char *p = start + 1;
const u8 *q;
u8 ch = cx->search_pack_header ? 0xba : 0xe0;
int stuffing, i;
while (start + len > p) {
q = memchr(p, 0, start + len - p);
if (q == NULL)
break;
p = q + 1;
if ((char *)q + 15 >= buf->buf + buf->bytesused ||
q[1] != 0 || q[2] != 1 || q[3] != ch)
continue;
if (!cx->search_pack_header) {
if ((q[6] & 0xc0) != 0x80)
continue;
if (((q[7] & 0xc0) == 0x80 &&
(q[9] & 0xf0) == 0x20) ||
((q[7] & 0xc0) == 0xc0 &&
(q[9] & 0xf0) == 0x30)) {
ch = 0xba;
cx->search_pack_header = 1;
p = q + 9;
}
continue;
}
stuffing = q[13] & 7;
/* all stuffing bytes must be 0xff */
for (i = 0; i < stuffing; i++)
if (q[14 + i] != 0xff)
break;
if (i == stuffing &&
(q[4] & 0xc4) == 0x44 &&
(q[12] & 3) == 3 &&
q[14 + stuffing] == 0 &&
q[15 + stuffing] == 0 &&
q[16 + stuffing] == 1) {
cx->search_pack_header = 0;
len = (char *)q - start;
cx18_setup_sliced_vbi_buf(cx);
break;
}
}
}
if (copy_to_user(ubuf, (u8 *)buf->buf + buf->readpos, len)) {
CX18_DEBUG_WARN("copy %zd bytes to user failed for %s\n",
len, s->name);
return -EFAULT;
}
buf->readpos += len;
if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
buf != &cx->vbi.sliced_mpeg_buf)
cx->mpg_data_received += len;
return len;
}
static size_t cx18_copy_buf_to_user(struct cx18_stream *s,
struct cx18_buffer *buf, char __user *ubuf, size_t ucount)
{
struct cx18 *cx = s->cx;
size_t len = buf->bytesused - buf->readpos;
if (len > ucount)
len = ucount;
if (cx->vbi.insert_mpeg && s->type == CX18_ENC_STREAM_TYPE_MPG &&
!cx18_raw_vbi(cx) && buf != &cx->vbi.sliced_mpeg_buf) {
/*
* Try to find a good splice point in the PS, just before
* an MPEG-2 Program Pack start code, and provide only
* up to that point to the user, so it's easy to insert VBI data
* the next time around.
*
* This will not work for an MPEG-2 TS and has only been
* verified by analysis to work for an MPEG-2 PS. Helen Buus
* pointed out this works for the CX23416 MPEG-2 DVD compatible
* stream, and research indicates both the MPEG 2 SVCD and DVD
* stream types use an MPEG-2 PS container.
*/
/*
* An MPEG-2 Program Stream (PS) is a series of
* MPEG-2 Program Packs terminated by an
* MPEG Program End Code after the last Program Pack.
* A Program Pack may hold a PS System Header packet and any
* number of Program Elementary Stream (PES) Packets
*/
const char *start = buf->buf + buf->readpos;
const char *p = start + 1;
const u8 *q;
u8 ch = cx->search_pack_header ? 0xba : 0xe0;
int stuffing, i;
while (start + len > p) {
/* Scan for a 0 to find a potential MPEG-2 start code */
q = memchr(p, 0, start + len - p);
if (q == NULL)
break;
p = q + 1;
/*
* Keep looking if not a
* MPEG-2 Pack header start code: 0x00 0x00 0x01 0xba
* or MPEG-2 video PES start code: 0x00 0x00 0x01 0xe0
*/
if ((char *)q + 15 >= buf->buf + buf->bytesused ||
q[1] != 0 || q[2] != 1 || q[3] != ch)
continue;
/* If expecting the primary video PES */
if (!cx->search_pack_header) {
/* Continue if it couldn't be a PES packet */
if ((q[6] & 0xc0) != 0x80)
continue;
/* Check if a PTS or PTS & DTS follow */
if (((q[7] & 0xc0) == 0x80 && /* PTS only */
(q[9] & 0xf0) == 0x20) || /* PTS only */
((q[7] & 0xc0) == 0xc0 && /* PTS & DTS */
(q[9] & 0xf0) == 0x30)) { /* DTS follows */
/* Assume we found the video PES hdr */
ch = 0xba; /* next want a Program Pack*/
cx->search_pack_header = 1;
p = q + 9; /* Skip this video PES hdr */
}
continue;
}
/* We may have found a Program Pack start code */
/* Get the count of stuffing bytes & verify them */
stuffing = q[13] & 7;
/* all stuffing bytes must be 0xff */
for (i = 0; i < stuffing; i++)
if (q[14 + i] != 0xff)
break;
if (i == stuffing && /* right number of stuffing bytes*/
(q[4] & 0xc4) == 0x44 && /* marker check */
(q[12] & 3) == 3 && /* marker check */
q[14 + stuffing] == 0 && /* PES Pack or Sys Hdr */
q[15 + stuffing] == 0 &&
q[16 + stuffing] == 1) {
/* We declare we actually found a Program Pack*/
cx->search_pack_header = 0; /* expect vid PES */
len = (char *)q - start;
cx18_setup_sliced_vbi_buf(cx);
break;
}
}
}
if (copy_to_user(ubuf, (u8 *)buf->buf + buf->readpos, len)) {
CX18_DEBUG_WARN("copy %zd bytes to user failed for %s\n",
len, s->name);
return -EFAULT;
}
buf->readpos += len;
if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
buf != &cx->vbi.sliced_mpeg_buf)
cx->mpg_data_received += len;
return len;
}
