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jpegdec: Adds 8bit grayscale support

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Adds decoding support for jpeg images in 8 bit grayscale format.
This commit is contained in:
Thiago Santos 2010-05-18 14:46:54 -03:00
parent d7a25fd109
commit bca4ca631f
1 changed files with 58 additions and 5 deletions
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63
ext/jpeg/gstjpegdec.c
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@ -67,7 +67,8 @@ GST_STATIC_PAD_TEMPLATE ("src",
GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420") "; "
GST_VIDEO_CAPS_RGB "; " GST_VIDEO_CAPS_BGR "; "
GST_VIDEO_CAPS_RGBx "; " GST_VIDEO_CAPS_xRGB "; "
GST_VIDEO_CAPS_BGRx "; " GST_VIDEO_CAPS_xBGR)
GST_VIDEO_CAPS_BGRx "; " GST_VIDEO_CAPS_xBGR "; "
GST_VIDEO_CAPS_GRAY8)
);
/* *INDENT-ON* */
@ -746,6 +747,42 @@ gst_jpeg_dec_ensure_buffers (GstJpegDec * dec, guint maxrowbytes)
return TRUE;
}
static void
gst_jpeg_dec_decode_grayscale (GstJpegDec * dec, guchar * base[1],
guint width, guint height, guint pstride, guint rstride)
{
guchar *rows[16];
guchar **scanarray[1] = { rows };
gint i, j, k;
gint lines;
GST_DEBUG_OBJECT (dec, "indirect decoding of grayscale");
if (G_UNLIKELY (!gst_jpeg_dec_ensure_buffers (dec, GST_ROUND_UP_32 (width))))
return;
memcpy (rows, dec->idr_y, 16 * sizeof (gpointer));
i = 0;
while (i < height) {
lines = jpeg_read_raw_data (&dec->cinfo, scanarray, DCTSIZE);
if (G_LIKELY (lines > 0)) {
for (j = 0; (j < DCTSIZE) && (i < height); j++, i++) {
gint p;
p = 0;
for (k = 0; k < width; k++) {
base[0][p] = rows[j][k];
p += pstride;
}
base[0] += rstride;
}
} else {
GST_INFO_OBJECT (dec, "jpeg_read_raw_data() returned 0");
}
}
}
static void
gst_jpeg_dec_decode_rgb (GstJpegDec * dec, guchar * base[3],
guint width, guint height, guint pstride, guint rstride)
@ -1092,6 +1129,16 @@ gst_jpeg_dec_negotiate (GstJpegDec * dec, gint width, gint height, gint clrspc)
/* equal for all components */
dec->stride = gst_video_format_get_row_stride (format, 0, width);
dec->inc = gst_video_format_get_pixel_stride (format, 0);
} else if (dec->cinfo.jpeg_color_space == JCS_GRAYSCALE) {
/* TODO is anything else then 8bit supported in jpeg? */
format = GST_VIDEO_FORMAT_GRAY8;
caps = gst_video_format_new_caps (format, width, height,
dec->framerate_numerator, dec->framerate_denominator, 1, 1);
dec->outsize = gst_video_format_get_size (format, width, height);
dec->offset[0] =
gst_video_format_get_component_offset (format, 0, width, height);
dec->stride = gst_video_format_get_row_stride (format, 0, width);
dec->inc = gst_video_format_get_pixel_stride (format, 0);
} else {
/* go for plain and simple I420 */
/* TODO other YUV cases ? */
@ -1258,11 +1305,13 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
/* sanity checks to get safe and reasonable output */
switch (dec->cinfo.jpeg_color_space) {
case JCS_GRAYSCALE:
if (dec->cinfo.num_components != 1)
goto invalid_yuvrgbgrayscale;
break;
case JCS_RGB:
if (dec->cinfo.num_components != 3 || dec->cinfo.max_v_samp_factor > 1 ||
dec->cinfo.max_h_samp_factor > 1)
goto invalid_yuvrgb;
goto invalid_yuvrgbgrayscale;
break;
case JCS_YCbCr:
if (dec->cinfo.num_components != 3 ||
@ -1270,7 +1319,7 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
r_v < dec->cinfo.comp_info[1].v_samp_factor ||
r_h < dec->cinfo.comp_info[0].h_samp_factor ||
r_h < dec->cinfo.comp_info[1].h_samp_factor)
goto invalid_yuvrgb;
goto invalid_yuvrgbgrayscale;
break;
default:
g_assert_not_reached ();
@ -1322,6 +1371,10 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
base[1] = outdata + dec->offset[1];
base[2] = outdata + dec->offset[2];
gst_jpeg_dec_decode_rgb (dec, base, width, height, dec->inc, dec->stride);
} else if (dec->cinfo.jpeg_color_space == JCS_GRAYSCALE) {
base[0] = outdata + dec->offset[0];
gst_jpeg_dec_decode_grayscale (dec, base, width, height, dec->inc,
dec->stride);
} else {
/* mind the swap, jpeglib outputs blue chroma first
* ensonic: I see no swap?
@ -1495,10 +1548,10 @@ unsupported_colorspace:
ret = GST_FLOW_ERROR;
goto done;
}
invalid_yuvrgb:
invalid_yuvrgbgrayscale:
{
GST_ELEMENT_ERROR (dec, STREAM, DECODE, (NULL),
("Picture is corrupt or unhandled YUV/RGB layout"));
("Picture is corrupt or unhandled YUV/RGB/grayscale layout"));
ret = GST_FLOW_ERROR;
goto done;
}