h264parse: optimize slice nal processing

Only minimal slice info is needed here to determine real frame start,
so no need to parse extensively.

Fixes #665418.
This commit is contained in:
Mark Nauwelaerts 2011-12-05 12:57:47 +01:00
parent 91e054ba58
commit ef24518b60

View file

@ -404,15 +404,12 @@ static void
gst_h264_parse_process_nal (GstH264Parse * h264parse, GstH264NalUnit * nalu)
{
guint nal_type;
GstH264SliceHdr slice;
GstH264PPS pps;
GstH264SPS sps;
GstH264SEIMessage sei;
gboolean slcparsed = FALSE;
gboolean slcparsed = FALSE, complete = FALSE;
GstH264NalParser *nalparser = h264parse->nalparser;
/* nothing to do for broken input */
if (G_UNLIKELY (nalu->size < 2)) {
GST_DEBUG_OBJECT (h264parse, "not processing nal size %u", nalu->size);
@ -476,30 +473,36 @@ gst_h264_parse_process_nal (GstH264Parse * h264parse, GstH264NalUnit * nalu)
case GST_H264_NAL_SLICE_DPB:
case GST_H264_NAL_SLICE_DPC:
slcparsed = TRUE;
if (gst_h264_parser_parse_slice_hdr (nalparser, nalu,
&slice, FALSE, FALSE) == GST_H264_PARSER_ERROR)
return;
/* don't need to parse the whole slice (header) here */
if (*(nalu->data + nalu->offset + 1) & 0x80) {
/* first_mb_in_slice == 0 completes a picture */
complete = TRUE;
}
/* real frame data */
h264parse->frame_start |= (slice.first_mb_in_slice == 0);
h264parse->frame_start |= complete;
/* if we need to sneak codec NALs into the stream,
* this is a good place, so fake it as IDR
* (which should be at start anyway) */
GST_DEBUG_OBJECT (h264parse, "frame start: %i first_mb_in_slice %i",
h264parse->frame_start, slice.first_mb_in_slice);
GST_DEBUG_OBJECT (h264parse,
"frame start: %i, first_mb_in_slice == 0: %d",
h264parse->frame_start, complete);
if (G_LIKELY (!h264parse->push_codec))
break;
/* fall-through */
case GST_H264_NAL_SLICE_IDR:
if (!slcparsed) {
if (gst_h264_parser_parse_slice_hdr (nalparser, nalu,
&slice, FALSE, FALSE) == GST_H264_PARSER_ERROR)
return;
GST_DEBUG_OBJECT (h264parse, "frame start: %i first_mb_in_slice %i",
h264parse->frame_start, slice.first_mb_in_slice);
/* don't need to parse the whole slice (header) here */
if (*(nalu->data + nalu->offset + 1) & 0x80) {
/* first_mb_in_slice == 0 completes a picture */
complete = TRUE;
}
GST_DEBUG_OBJECT (h264parse,
"frame start: %i, first_mb_in_slice == 0: %d",
h264parse->frame_start, complete);
}
/* real frame data */
h264parse->frame_start |= (slice.first_mb_in_slice == 0);
h264parse->frame_start |= complete;
/* mark where config needs to go if interval expired */
/* mind replacement buffer if applicable */
@ -511,9 +514,18 @@ gst_h264_parse_process_nal (GstH264Parse * h264parse, GstH264NalUnit * nalu)
GST_DEBUG_OBJECT (h264parse, "marking IDR in frame at offset %d",
h264parse->idr_pos);
}
#ifndef GST_DISABLE_GST_DEBUG
{
GstH264SliceHdr slice;
GstH264ParserResult pres;
GST_DEBUG_OBJECT (h264parse, "first MB: %u, slice type: %u",
slice.first_mb_in_slice, slice.type);
pres = gst_h264_parser_parse_slice_hdr (nalparser, nalu, &slice,
FALSE, FALSE);
GST_DEBUG_OBJECT (h264parse,
"parse result %d, first MB: %u, slice type: %u",
pres, slice.first_mb_in_slice, slice.type);
}
#endif
break;
default:
gst_h264_parser_parse_nal (nalparser, nalu);