avutil/pixdesc: add alpha component information to pixfmts with reserved but undefined alpha bits

This can be useful to simplify certain processes that need to know how many
reserved bits there are and where they are placed, even if they are ultimately
unused, as will be shown in the next commit.
For any other case where the user simply looks at nb_components components, it
will make no difference.

Signed-off-by: James Almer <jamrial@gmail.com>

2 files changed, 18 insertions, 4 deletions

diff --git a/libavutil/pixdesc.c b/libavutil/pixdesc.c
index 4d61e32a1e..225a4a15db 100644
--- a/libavutil/pixdesc.c
+++ b/libavutil/pixdesc.c
@@ -49,7 +49,7 @@ void av_read_image_line2(void *dst,
         return;
 
     if (flags & AV_PIX_FMT_FLAG_BITSTREAM) {
-        if (depth == 10) {
+        if (step > 8) {
             // Assume all channels are packed into a 32bit value
             const uint8_t *byte_p = data[plane] + y * linesize[plane];
             const uint32_t *p = (uint32_t *)byte_p;
@@ -131,7 +131,7 @@ void av_write_image_line2(const void *src,
         return;
 
     if (flags & AV_PIX_FMT_FLAG_BITSTREAM) {
-        if (depth == 10) {
+        if (step > 8) {
             // Assume all channels are packed into a 32bit value
             const uint8_t *byte_p = data[plane] + y * linesize[plane];
             uint32_t *p = (uint32_t *)byte_p;
@@ -291,6 +291,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 2, 4, 10 },       /* R */
             { 0, 4, 1, 2, 10 },       /* G */
             { 0, 4, 0, 0, 10 },       /* B */
+            { 0, 4, 3, 6,  2 },       /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB,
     },
@@ -303,6 +304,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 0, 4, 10 },       /* R */
             { 0, 4, 1, 2, 10 },       /* G */
             { 0, 4, 2, 0, 10 },       /* B */
+            { 0, 4, 0, 6,  2 },       /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB | AV_PIX_FMT_FLAG_BE,
     },
@@ -315,6 +317,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 0, 0, 10 },       /* R */
             { 0, 4, 1, 2, 10 },       /* G */
             { 0, 4, 2, 4, 10 },       /* B */
+            { 0, 4, 3, 6,  2 },       /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB,
     },
@@ -327,6 +330,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 2, 0, 10 },       /* R */
             { 0, 4, 1, 2, 10 },       /* G */
             { 0, 4, 0, 4, 10 },       /* B */
+            { 0, 4, 0, 6,  2 },       /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB | AV_PIX_FMT_FLAG_BE,
     },
@@ -645,6 +649,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 1, 0, 8 },        /* R */
             { 0, 4, 2, 0, 8 },        /* G */
             { 0, 4, 3, 0, 8 },        /* B */
+            { 0, 4, 0, 0, 8 },        /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB,
     },
@@ -657,6 +662,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 0, 0, 8 },        /* R */
             { 0, 4, 1, 0, 8 },        /* G */
             { 0, 4, 2, 0, 8 },        /* B */
+            { 0, 4, 3, 0, 8 },        /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB,
     },
@@ -669,6 +675,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 3, 0, 8 },        /* R */
             { 0, 4, 2, 0, 8 },        /* G */
             { 0, 4, 1, 0, 8 },        /* B */
+            { 0, 4, 0, 0, 8 },        /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB,
     },
@@ -681,6 +688,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 2, 0, 8 },        /* R */
             { 0, 4, 1, 0, 8 },        /* G */
             { 0, 4, 0, 0, 8 },        /* B */
+            { 0, 4, 3, 0, 8 },        /* X */
         },
         .flags = AV_PIX_FMT_FLAG_RGB,
     },
@@ -2634,6 +2642,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 2, 0, 8 },        /* Y */
             { 0, 4, 1, 0, 8 },        /* U */
             { 0, 4, 0, 0, 8 },        /* V */
+            { 0, 4, 3, 0, 8 },        /* X */
         },
     },
     [AV_PIX_FMT_RGBF16BE] = {
@@ -2721,6 +2730,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 1, 2, 10 },       /* Y */
             { 0, 4, 0, 0, 10 },       /* U */
             { 0, 4, 2, 4, 10 },       /* V */
+            { 0, 4, 3, 6,  2 },       /* X */
         },
     },
     [AV_PIX_FMT_XV30BE] = {
@@ -2732,6 +2742,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 32, 10, 0, 10 },       /* Y */
             { 0, 32,  0, 0, 10 },       /* U */
             { 0, 32, 20, 0, 10 },       /* V */
+            { 0, 32, 30, 0,  2 },       /* X */
         },
         .flags = AV_PIX_FMT_FLAG_BE | AV_PIX_FMT_FLAG_BITSTREAM,
     },
@@ -2744,6 +2755,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 8, 2, 4, 12 },       /* Y */
             { 0, 8, 0, 4, 12 },       /* U */
             { 0, 8, 4, 4, 12 },       /* V */
+            { 0, 8, 6, 4, 12 },       /* X */
         },
     },
     [AV_PIX_FMT_XV36BE] = {
@@ -2755,6 +2767,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 8, 2, 4, 12 },       /* Y */
             { 0, 8, 0, 4, 12 },       /* U */
             { 0, 8, 4, 4, 12 },       /* V */
+            { 0, 8, 6, 4, 12 },       /* X */
         },
         .flags = AV_PIX_FMT_FLAG_BE,
     },
@@ -2767,6 +2780,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 4, 1, 4, 10 },       /* Y */
             { 0, 4, 0, 2, 10 },       /* U */
             { 0, 4, 2, 6, 10 },       /* V */
+            { 0, 4, 0, 0,  2 },       /* X */
         },
     },
     [AV_PIX_FMT_V30XBE] = {
@@ -2778,6 +2792,7 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
             { 0, 32, 12, 0, 10 },     /* Y */
             { 0, 32,  2, 0, 10 },     /* U */
             { 0, 32, 22, 0, 10 },     /* V */
+            { 0, 32,  0, 0,  2 },     /* X */
         },
         .flags = AV_PIX_FMT_FLAG_BE | AV_PIX_FMT_FLAG_BITSTREAM,
     },
diff --git a/libavutil/tests/pixelutils.c b/libavutil/tests/pixelutils.c
index 828a7580d2..b374de04bb 100644
--- a/libavutil/tests/pixelutils.c
+++ b/libavutil/tests/pixelutils.c
@@ -58,8 +58,7 @@ static void check_pixfmt_descriptors(void)
 
         for (int j = 0; j < FF_ARRAY_ELEMS(d->comp); j++) {
             const AVComponentDescriptor *c = &d->comp[j];
-            if (j >= d->nb_components) {
-                av_assert0(!c->plane && !c->step && !c->offset && !c->shift && !c->depth);
+            if (!c->depth) {
                 continue;
             }
             if (d->flags & AV_PIX_FMT_FLAG_BITSTREAM) {