From ac29054fda1fab73c443b7d6f9dd72a9f25f7aae Mon Sep 17 00:00:00 2001
From: Janne Grunau <janne-libav@jannau.net>
Date: Mon, 2 Jul 2012 11:15:06 +0200
Subject: [PATCH] imgconvert: add avcodec_find_best_pix_fmt2()
The number of pixel formats outgrew the number of available bits in
the bitmask used in avcodec_find_best_pix_fmt().
avcodec_find_best_pix_fmt2() uses a PIX_FMT_NONE terminated list
of pixel formats instead.
---
libavcodec/avcodec.h | 21 ++++++++++++++++++
libavcodec/imgconvert.c | 48 ++++++++++++++++++++++++++++++-----------
libavcodec/version.h | 2 +-
3 files changed, 58 insertions(+), 13 deletions(-)
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index e397bbca837..9e1aa1c9278 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -4227,6 +4227,27 @@ int avcodec_get_pix_fmt_loss(enum PixelFormat dst_pix_fmt, enum PixelFormat src_
enum PixelFormat avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, enum PixelFormat src_pix_fmt,
int has_alpha, int *loss_ptr);
+/**
+ * Find the best pixel format to convert to given a certain source pixel
+ * format. When converting from one pixel format to another, information loss
+ * may occur. For example, when converting from RGB24 to GRAY, the color
+ * information will be lost. Similarly, other losses occur when converting from
+ * some formats to other formats. avcodec_find_best_pix_fmt2() searches which of
+ * the given pixel formats should be used to suffer the least amount of loss.
+ * The pixel formats from which it chooses one, are determined by the
+ * pix_fmt_list parameter.
+ *
+ *
+ * @param[in] pix_fmt_list PIX_FMT_NONE terminated array of pixel formats to choose from
+ * @param[in] src_pix_fmt source pixel format
+ * @param[in] has_alpha Whether the source pixel format alpha channel is used.
+ * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
+ * @return The best pixel format to convert to or -1 if none was found.
+ */
+enum PixelFormat avcodec_find_best_pix_fmt2(enum PixelFormat *pix_fmt_list,
+ enum PixelFormat src_pix_fmt,
+ int has_alpha, int *loss_ptr);
+
enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum PixelFormat * fmt);
/**
diff --git a/libavcodec/imgconvert.c b/libavcodec/imgconvert.c
index 7a6102e08bd..5b22cab023f 100644
--- a/libavcodec/imgconvert.c
+++ b/libavcodec/imgconvert.c
@@ -588,7 +588,7 @@ static int avg_bits_per_pixel(enum PixelFormat pix_fmt)
return bits;
}
-static enum PixelFormat avcodec_find_best_pix_fmt1(int64_t pix_fmt_mask,
+static enum PixelFormat avcodec_find_best_pix_fmt1(enum PixelFormat *pix_fmt_list,
enum PixelFormat src_pix_fmt,
int has_alpha,
int loss_mask)
@@ -599,24 +599,48 @@ static enum PixelFormat avcodec_find_best_pix_fmt1(int64_t pix_fmt_mask,
/* find exact color match with smallest size */
dst_pix_fmt = PIX_FMT_NONE;
min_dist = 0x7fffffff;
- /* test only the first 64 pixel formats to avoid undefined behaviour */
- for (i = 0; i < 64; i++) {
- if (pix_fmt_mask & (1ULL << i)) {
- loss = avcodec_get_pix_fmt_loss(i, src_pix_fmt, has_alpha) & loss_mask;
- if (loss == 0) {
- dist = avg_bits_per_pixel(i);
- if (dist < min_dist) {
- min_dist = dist;
- dst_pix_fmt = i;
- }
+ i = 0;
+ while (pix_fmt_list[i] != PIX_FMT_NONE) {
+ enum PixelFormat pix_fmt = pix_fmt_list[i];
+
+ if (i > PIX_FMT_NB) {
+ av_log(NULL, AV_LOG_ERROR, "Pixel format list longer than expected, "
+ "it is either not properly terminated or contains duplicates\n");
+ return PIX_FMT_NONE;
+ }
+
+ loss = avcodec_get_pix_fmt_loss(pix_fmt, src_pix_fmt, has_alpha) & loss_mask;
+ if (loss == 0) {
+ dist = avg_bits_per_pixel(pix_fmt);
+ if (dist < min_dist) {
+ min_dist = dist;
+ dst_pix_fmt = pix_fmt;
}
}
+ i++;
}
return dst_pix_fmt;
}
enum PixelFormat avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, enum PixelFormat src_pix_fmt,
int has_alpha, int *loss_ptr)
+{
+ enum PixelFormat list[64];
+ int i, j = 0;
+
+ // test only the first 64 pixel formats to avoid undefined behaviour
+ for (i = 0; i < 64; i++) {
+ if (pix_fmt_mask & (1ULL << i))
+ list[j++] = i;
+ }
+ list[j] = PIX_FMT_NONE;
+
+ return avcodec_find_best_pix_fmt2(list, src_pix_fmt, has_alpha, loss_ptr);
+}
+
+enum PixelFormat avcodec_find_best_pix_fmt2(enum PixelFormat *pix_fmt_list,
+ enum PixelFormat src_pix_fmt,
+ int has_alpha, int *loss_ptr)
{
enum PixelFormat dst_pix_fmt;
int loss_mask, i;
@@ -634,7 +658,7 @@ enum PixelFormat avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, enum PixelForma
i = 0;
for(;;) {
loss_mask = loss_mask_order[i++];
- dst_pix_fmt = avcodec_find_best_pix_fmt1(pix_fmt_mask, src_pix_fmt,
+ dst_pix_fmt = avcodec_find_best_pix_fmt1(pix_fmt_list, src_pix_fmt,
has_alpha, loss_mask);
if (dst_pix_fmt >= 0)
goto found;
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 6cdb92a4ae5..ff13f9d22db 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -27,7 +27,7 @@
*/
#define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR 20
+#define LIBAVCODEC_VERSION_MINOR 21
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
--
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