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jpeg: fix determination of image bounds.

Browse source 
Look for the exact image bounds characterised by the <SOI> and <EOI>
markers. Use the gst_jpeg_parse() codec parser utility function to
optimize the lookup for the next marker segment.

https://bugzilla.gnome.org/show_bug.cgi?id=707447
This commit is contained in:
Gwenole Beauchesne 2013-09-18 17:59:44 +02:00
parent 9c29bbde58
commit 77298beb15
1 changed files with 44 additions and 17 deletions
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61
gst-libs/gst/vaapi/gstvaapidecoder_jpeg.c
View file

@ -647,11 +647,21 @@ ensure_decoder(GstVaapiDecoderJpeg *decoder)
return GST_VAAPI_DECODER_STATUS_SUCCESS;
}
static inline gint
scan_for_start_code(GstAdapter *adapter, guint ofs, guint size, guint32 *scp)
static gint
scan_for_marker_code(const guchar *buf, guint buf_size,
GstJpegMarkerCode marker)
{
return (gint)gst_adapter_masked_scan_uint32_peek(adapter,
0xffff0000, 0xffd80000, ofs, size, scp);
GstJpegMarkerSegment seg;
guint ofs = 0;
while (gst_jpeg_parse(&seg, buf, buf_size, ofs)) {
if (seg.size < 0)
return -1;
if (seg.marker == marker)
return seg.offset - 2;
ofs = seg.offset + seg.size;
}
return -1;
}
static GstVaapiDecoderStatus
@ -660,37 +670,54 @@ gst_vaapi_decoder_jpeg_parse(GstVaapiDecoder *base_decoder,
{
GstVaapiDecoderJpeg * const decoder =
GST_VAAPI_DECODER_JPEG_CAST(base_decoder);
GstVaapiParserState * const ps = GST_VAAPI_PARSER_STATE(base_decoder);
GstVaapiDecoderStatus status;
guint size, buf_size, flags = 0;
gint ofs;
const guchar *buf;
guint buf_size, flags;
gint ofs, ofs1, ofs2;
status = ensure_decoder(decoder);
if (status != GST_VAAPI_DECODER_STATUS_SUCCESS)
return status;
/* Expect at least 4 bytes, SOI .. EOI */
size = gst_adapter_available(adapter);
if (size < 4)
buf_size = gst_adapter_available(adapter);
if (buf_size < 4)
return GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA;
ofs = scan_for_start_code(adapter, 0, size, NULL);
if (ofs < 0)
buf = gst_adapter_map(adapter, buf_size);
if (!buf)
return GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA;
gst_adapter_flush(adapter, ofs);
size -= ofs;
ofs = G_UNLIKELY(size < 4) ? -1 :
scan_for_start_code(adapter, 2, size - 2, NULL);
ofs = scan_for_marker_code(buf, buf_size, GST_JPEG_MARKER_SOI);
if (ofs < 0) {
gst_adapter_unmap(adapter);
return GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA;
}
ofs1 = ofs;
ofs2 = ps->input_offset2 - 2;
if (ofs2 < ofs1 + 2)
ofs2 = ofs1 + 2;
ofs = G_UNLIKELY(buf_size < ofs2 + 2) ? -1 :
scan_for_marker_code(&buf[ofs2], buf_size - ofs2, GST_JPEG_MARKER_EOI);
gst_adapter_unmap(adapter);
if (ofs < 0) {
// Assume the whole packet is present if end-of-stream
if (!at_eos)
if (!at_eos) {
ps->input_offset2 = buf_size;
return GST_VAAPI_DECODER_STATUS_ERROR_NO_DATA;
ofs = size;
}
ofs = buf_size - ofs2;
}
buf_size = ofs;
ofs2 += ofs;
unit->size = buf_size;
gst_adapter_flush(adapter, ofs1);
ps->input_offset2 = 2;
flags = 0;
flags |= GST_VAAPI_DECODER_UNIT_FLAG_FRAME_START;
flags |= GST_VAAPI_DECODER_UNIT_FLAG_FRAME_END;
flags |= GST_VAAPI_DECODER_UNIT_FLAG_SLICE;