m_pvr_thread = 0;
- m_skipmode_n = m_skipmode_m = 0;
+ m_skipmode_n = m_skipmode_m = m_skipmode_frames = 0;
if (m_frontend)
m_frontend->get().connectStateChange(slot(*this, &eDVBChannel::frontendStateChanged), m_conn_frontendStateChanged);
/* i agree that this might look a bit like black magic. */
m_skipmode_n = 512*1024; /* must be 1 iframe at least. */
m_skipmode_m = bitrate / 8 / 90000 * m_cue->m_skipmode_ratio / 8;
+ m_skipmode_frames = m_cue->m_skipmode_ratio / 90000;
+ m_skipmode_frames_remainder = 0;
if (m_cue->m_skipmode_ratio < 0)
m_skipmode_m -= m_skipmode_n;
if (abs(m_skipmode_m) < abs(m_skipmode_n))
{
eWarning("something is wrong with this calculation");
- m_skipmode_n = m_skipmode_m = 0;
+ m_skipmode_frames = m_skipmode_n = m_skipmode_m = 0;
}
} else
{
eDebug("skipmode ratio is 0, normal play");
- m_skipmode_n = m_skipmode_m = 0;
+ m_skipmode_frames = m_skipmode_n = m_skipmode_m = 0;
}
}
m_pvr_thread->setIFrameSearch(m_skipmode_n != 0);
return x;
}
+ /* align toward zero */
+static inline long long align_with_len(long long x, int align, size_t &len)
+{
+ int sign = x < 0;
+
+ if (sign)
+ x = -x;
+
+ x -= x % align;
+ len += x % align;
+
+ if (sign)
+ x = -x;
+
+ return x;
+}
+
/* remember, this gets called from another thread. */
void eDVBChannel::getNextSourceSpan(off_t current_offset, size_t bytes_read, off_t &start, size_t &size)
{
if (m_skipmode_n)
{
- eDebug("skipmode %d:%d", m_skipmode_m, m_skipmode_n);
+ eDebug("skipmode %d:%d (x%d)", m_skipmode_m, m_skipmode_n, m_skipmode_frames);
max = align(m_skipmode_n, blocksize);
}
eDebug("getNextSourceSpan, current offset is %08llx, m_skipmode_m = %d!", current_offset, m_skipmode_m);
-
- current_offset += align(m_skipmode_m, blocksize);
+ int frame_skip_success = 0;
+
if (m_skipmode_m)
{
- eDebug("we are at %llx, and we try to find the iframe here:", current_offset);
+ int frames_to_skip = m_skipmode_frames + m_skipmode_frames_remainder;
+ eDebug("we are at %llx, and we try to skip %d+%d frames from here", current_offset, m_skipmode_frames, m_skipmode_frames_remainder);
size_t iframe_len;
off_t iframe_start = current_offset;
+ int frames_skipped = frames_to_skip;
+ if (!m_tstools.findNextPicture(iframe_start, iframe_len, frames_skipped))
+ {
+ m_skipmode_frames_remainder = frames_to_skip - frames_skipped;
+ eDebug("successfully skipped %d (out of %d, rem now %d) frames.", frames_skipped, frames_to_skip, m_skipmode_frames_remainder);
+ current_offset = align_with_len(iframe_start, blocksize, iframe_len);
+ max = align(iframe_len + 187, blocksize);
+ frame_skip_success = 1;
+ } else
+ {
+ m_skipmode_frames_remainder = 0;
+ eDebug("frame skipping failed, reverting to byte-skipping");
+ }
+ }
+
+ if (!frame_skip_success)
+ {
+ current_offset += align(m_skipmode_m, blocksize);
- if (m_tstools.findIFrame(iframe_start, iframe_len, (m_skipmode_m < 0) ? -1 : +1))
- eDebug("failed");
- else
+ if (m_skipmode_m)
{
- current_offset = align(iframe_start, blocksize);
- max = align(iframe_len, blocksize);
+ eDebug("we are at %llx, and we try to find the iframe here:", current_offset);
+ size_t iframe_len;
+ off_t iframe_start = current_offset;
+
+ int direction = (m_skipmode_m < 0) ? -1 : +1;
+ if (m_tstools.findFrame(iframe_start, iframe_len, direction))
+ eDebug("failed");
+ else
+ {
+ current_offset = align_with_len(iframe_start, blocksize, iframe_len);
+ max = align(iframe_len, blocksize);
+ }
}
}
size_t iframe_len;
/* try to align to iframe */
- m_tstools.findIFrame(offset, iframe_len, pts < 0 ? -1 : 1);
+ int direction = pts < 0 ? -1 : 1;
+ m_tstools.findFrame(offset, iframe_len, direction);
- eDebug("ok, resolved skip (rel: %d, diff %lld), now at %08llx", relative, pts, offset);
+ eDebug("ok, resolved skip (rel: %d, diff %lld), now at %08llx (skipped additional %d frames due to iframe re-align)", relative, pts, offset, direction);
current_offset = align(offset, blocksize); /* in case tstools return non-aligned offset */
}
return -1;
}
-int eDVBTSTools::findIFrame(off_t &_offset, size_t &len, int direction)
+int eDVBTSTools::findFrame(off_t &_offset, size_t &len, int &direction, int frame_types)
{
off_t offset = _offset;
+ int nr_frames = 0;
// eDebug("trying to find iFrame at %llx", offset);
if (!m_use_streaminfo)
{
- eDebug("can't get next iframe without streaminfo");
+// eDebug("can't get next iframe without streaminfo");
return -1;
}
/* let's find the iframe before the given offset */
unsigned long long data;
+
+ if (direction < 0)
+ offset--;
+
while (1)
{
if (m_streaminfo.getStructureEntry(offset, data, (direction == 0) ? 1 : 0))
}
/* data is usually the start code in the lower 8 bit, and the next byte <<8. we extract the picture type from there */
/* we know that we aren't recording startcode 0x09 for mpeg2, so this is safe */
+ /* TODO: check frame_types */
int is_start = (data & 0xE0FF) == 0x0009; /* H.264 NAL unit access delimiter with I-frame*/
is_start |= (data & 0x3800FF) == 0x080000; /* MPEG2 picture start code with I-frame */
-// eDebug("%08llx@%llx -> %d", data, offset, is_start);
+
+ int is_frame = ((data & 0xFF) == 0x0009) || ((data & 0xFF) == 0x00); /* H.264 UAD or MPEG2 start code */
+
+ if (is_frame)
+ {
+ if (direction < 0)
+ --nr_frames;
+ else
+ ++nr_frames;
+ }
+// eDebug("%08llx@%llx -> %d, %d", data, offset, is_start, nr_frames);
if (is_start)
break;
eDebug("reached eof (while looking for end of iframe)");
return -1;
}
-// eDebug("%08llx@%llx", data, offset);
+// eDebug("%08llx@%llx (next)", data, offset);
} while (((data & 0xFF) != 9) && ((data & 0xFF) != 0x00)); /* next frame */
/* align to TS pkt start */
- start = start - (start % 188);
- offset = offset - (offset % 188);
+// start = start - (start % 188);
+// offset = offset - (offset % 188);
len = offset - start;
_offset = start;
+ direction = nr_frames;
// eDebug("result: offset=%llx, len: %ld", offset, (int)len);
return 0;
}
+
+int eDVBTSTools::findNextPicture(off_t &offset, size_t &len, int &distance, int frame_types)
+{
+ int nr_frames = 0;
+// eDebug("trying to move %d frames at %llx", distance, offset);
+
+ frame_types = frametypeI; /* TODO: intelligent "allow IP frames when not crossing an I-Frame */
+
+ int direction = distance > 0 ? 0 : -1;
+ distance = abs(distance);
+
+ off_t new_offset = offset;
+ size_t new_len = len;
+
+ while (distance > 0)
+ {
+ int dir = direction;
+ if (findFrame(new_offset, new_len, dir, frame_types))
+ {
+// eDebug("findFrame failed!\n");
+ return -1;
+ }
+
+ distance -= abs(dir);
+
+// eDebug("we moved %d, %d to go frames (now at %llx)", dir, distance, new_offset);
+
+ if (distance >= 0)
+ {
+ offset = new_offset;
+ len = new_len;
+ nr_frames += abs(dir);
+ }
+ }
+
+ distance = (direction < 0) ? -nr_frames : nr_frames;
+// eDebug("in total, we moved %d frames", nr_frames);
+
+ return 0;
+}
int findPMT(int &pmt_pid, int &service_id);
- int findIFrame(off_t &offset, size_t &len, int direction);
+ enum {
+ frametypeI = 1,
+ frametypeP = 2,
+ frametypeB = 4,
+ frametypeAll = frametypeI | frametypeP | frametypeB
+ };
+ /** findFrame: finds a specific frame at a given position
+
+ findFrame will look for the specified frame type starting at the given position, moving forward
+ (when direction is >0) or backward (when direction is <0). (direction=0 is a special case and also moves
+ forward, but starts with the last frame.)
+
+ return values are the new offset, the length of the found frame (both unaligned), and the (signed)
+ number of frames skipped. */
+ int findFrame(off_t &offset, size_t &len, int &direction, int frame_types = frametypeI);
+ int findNextPicture(off_t &offset, size_t &len, int &distance, int frame_types = frametypeAll);
private:
int m_pid;
int m_maxrange;