videoconvert: be smarter when selecting a conversion

Try to select the conversion that would result in the minimal amount of quality
loss. Quality loss is calculated rather arbitrarily but it avoids doing
something really stupid in most cases.
This commit is contained in:
Wim Taymans 2013-03-28 18:13:10 +01:00
parent 3532323817
commit 33a54ba4f3

View file

@ -136,13 +136,149 @@ gst_video_convert_caps_remove_format_info (GstCaps * caps)
return res; return res;
} }
#define SCORE_PALETTE_LOSS 1
#define SCORE_COLOR_LOSS 2
#define SCORE_ALPHA_LOSS 4
#define SCORE_CHROMA_W_LOSS 8
#define SCORE_CHROMA_H_LOSS 16
#define SCORE_DEPTH_LOSS 32
#define COLOR_MASK (GST_VIDEO_FORMAT_FLAG_YUV | \
GST_VIDEO_FORMAT_FLAG_RGB | GST_VIDEO_FORMAT_FLAG_GRAY)
#define ALPHA_MASK (GST_VIDEO_FORMAT_FLAG_ALPHA)
#define PALETTE_MASK (GST_VIDEO_FORMAT_FLAG_PALETTE)
/* calculate how much loss a conversion would be */
static void
score_value (GstBaseTransform * base, const GstVideoFormatInfo * in_info,
const GValue * val, gint * min_loss, const GstVideoFormatInfo ** out_info)
{
const gchar *fname;
const GstVideoFormatInfo *t_info;
GstVideoFormatFlags in_flags, t_flags;
gint loss;
fname = g_value_get_string (val);
t_info = gst_video_format_get_info (gst_video_format_from_string (fname));
if (!t_info)
return;
/* accept input format immediately without loss */
if (in_info == t_info) {
*min_loss = 0;
*out_info = t_info;
return;
}
loss = 1;
in_flags = GST_VIDEO_FORMAT_INFO_FLAGS (in_info);
in_flags &= ~GST_VIDEO_FORMAT_FLAG_LE;
in_flags &= ~GST_VIDEO_FORMAT_FLAG_COMPLEX;
in_flags &= ~GST_VIDEO_FORMAT_FLAG_UNPACK;
t_flags = GST_VIDEO_FORMAT_INFO_FLAGS (t_info);
t_flags &= ~GST_VIDEO_FORMAT_FLAG_LE;
t_flags &= ~GST_VIDEO_FORMAT_FLAG_COMPLEX;
t_flags &= ~GST_VIDEO_FORMAT_FLAG_UNPACK;
if ((t_flags & PALETTE_MASK) != (in_flags & PALETTE_MASK))
loss += SCORE_PALETTE_LOSS;
if ((t_flags & COLOR_MASK) != (in_flags & COLOR_MASK))
loss += SCORE_COLOR_LOSS;
if ((t_flags & ALPHA_MASK) != (in_flags & ALPHA_MASK))
loss += SCORE_ALPHA_LOSS;
if ((in_info->h_sub[1]) < (t_info->h_sub[1]))
loss += SCORE_CHROMA_H_LOSS;
if ((in_info->w_sub[1]) < (t_info->w_sub[1]))
loss += SCORE_CHROMA_W_LOSS;
if ((in_info->bits) > (t_info->bits))
loss += SCORE_DEPTH_LOSS;
GST_DEBUG_OBJECT (base, "score %s -> %s = %d",
GST_VIDEO_FORMAT_INFO_NAME (in_info),
GST_VIDEO_FORMAT_INFO_NAME (t_info), loss);
if (loss < *min_loss) {
GST_DEBUG_OBJECT (base, "found new best %d", loss);
*out_info = t_info;
*min_loss = loss;
}
}
static void
gst_video_convert_fixate_format (GstBaseTransform * base, GstCaps * caps,
GstCaps * result)
{
GstStructure *ins, *outs;
const gchar *in_format;
const GstVideoFormatInfo *in_info, *out_info = NULL;
gint min_loss = G_MAXINT;
guint i, capslen;
ins = gst_caps_get_structure (caps, 0);
in_format = gst_structure_get_string (ins, "format");
if (!in_format)
return;
GST_DEBUG_OBJECT (base, "source format %s", in_format);
in_info =
gst_video_format_get_info (gst_video_format_from_string (in_format));
if (!in_info)
return;
outs = gst_caps_get_structure (result, 0);
capslen = gst_caps_get_size (result);
GST_DEBUG_OBJECT (base, "iterate %d structures", capslen);
for (i = 0; i < capslen; i++) {
GstStructure *tests;
const GValue *format;
tests = gst_caps_get_structure (result, i);
format = gst_structure_get_value (tests, "format");
/* should not happen */
if (format == NULL)
continue;
if (GST_VALUE_HOLDS_LIST (format)) {
gint j, len;
len = gst_value_list_get_size (format);
GST_DEBUG_OBJECT (base, "have %d formats", len);
for (j = 0; j < len; j++) {
const GValue *val;
val = gst_value_list_get_value (format, j);
if (G_VALUE_HOLDS_STRING (val)) {
score_value (base, in_info, val, &min_loss, &out_info);
if (min_loss == 0)
break;
}
}
} else if (G_VALUE_HOLDS_STRING (format)) {
score_value (base, in_info, format, &min_loss, &out_info);
}
}
if (out_info)
gst_structure_set (outs, "format", G_TYPE_STRING,
GST_VIDEO_FORMAT_INFO_NAME (out_info), NULL);
}
static GstCaps * static GstCaps *
gst_video_convert_fixate_caps (GstBaseTransform * trans, gst_video_convert_fixate_caps (GstBaseTransform * trans,
GstPadDirection direction, GstCaps * caps, GstCaps * othercaps) GstPadDirection direction, GstCaps * caps, GstCaps * othercaps)
{ {
GstCaps *result; GstCaps *result;
GST_DEBUG_OBJECT (trans, "fixating caps %" GST_PTR_FORMAT, othercaps); GST_DEBUG_OBJECT (trans, "trying to fixate othercaps %" GST_PTR_FORMAT
" based on caps %" GST_PTR_FORMAT, othercaps, caps);
result = gst_caps_intersect (othercaps, caps); result = gst_caps_intersect (othercaps, caps);
if (gst_caps_is_empty (result)) { if (gst_caps_is_empty (result)) {
@ -152,6 +288,11 @@ gst_video_convert_fixate_caps (GstBaseTransform * trans,
gst_caps_unref (othercaps); gst_caps_unref (othercaps);
} }
GST_DEBUG_OBJECT (trans, "now fixating %" GST_PTR_FORMAT, result);
result = gst_caps_make_writable (result);
gst_video_convert_fixate_format (trans, caps, result);
/* fixate remaining fields */ /* fixate remaining fields */
result = gst_caps_fixate (result); result = gst_caps_fixate (result);