[FFmpeg-devel] [PATCH 1/2] dpx: 10 and 12 bit decoding

[Georg Lippitsch]

Rewrite 10 bit dpx decoder to decode into GBRP10 color space
instead of converting to RGB48.
Add 12 bit decoder to decode into GBRP12 color space.

The new 10 bit decoder brakes FATE.
---
 libavcodec/dpx.c |   87 +++++++++++++++++++++++++++++++++++------------------
 1 files changed, 57 insertions(+), 30 deletions(-)

diff --git a/libavcodec/dpx.c b/libavcodec/dpx.c
index 5e35005..71cf439 100644
--- a/libavcodec/dpx.c
+++ b/libavcodec/dpx.c
@@ -41,14 +41,6 @@ static unsigned int read32(const uint8_t **ptr, int is_big)
     return temp;
 }
 
-static inline unsigned make_16bit(unsigned value)
-{
-    // mask away invalid bits
-    value &= 0xFFC0;
-    // correctly expand to 16 bits
-    return value + (value >> 10);
-}
-
 static int decode_frame(AVCodecContext *avctx,
                         void *data,
                         int *data_size,
@@ -60,12 +52,13 @@ static int decode_frame(AVCodecContext *avctx,
     DPXContext *const s = avctx->priv_data;
     AVFrame *picture  = data;
     AVFrame *const p = &s->picture;
-    uint8_t *ptr;
+    uint8_t *ptr[AV_NUM_DATA_POINTERS];
 
     unsigned int offset;
     int magic_num, endian;
-    int x, y;
+    int x, y, i;
     int w, h, stride, bits_per_color, descriptor, elements, target_packet_size, source_packet_size;
+    int planar;
 
     unsigned int rgbBuffer;
 
@@ -138,13 +131,24 @@ static int decode_frame(AVCodecContext *avctx,
             }
             source_packet_size = elements;
             target_packet_size = elements;
+            planar = 0;
             break;
         case 10:
-            avctx->pix_fmt = PIX_FMT_RGB48;
+            avctx->pix_fmt = PIX_FMT_GBRP10;
             target_packet_size = 6;
             source_packet_size = 4;
+            planar = 1;
             break;
         case 12:
+            if (endian) {
+                avctx->pix_fmt = elements == 4 ? PIX_FMT_GBRP12BE : PIX_FMT_GBRP12BE;
+            } else {
+                avctx->pix_fmt = elements == 4 ? PIX_FMT_GBRP12LE : PIX_FMT_GBRP12LE;
+            }
+            target_packet_size = 6;
+            source_packet_size = 6;
+            planar = 1;
+            break;
         case 16:
             if (endian) {
                 avctx->pix_fmt = elements == 4 ? PIX_FMT_RGBA64BE : PIX_FMT_RGB48BE;
@@ -153,6 +157,7 @@ static int decode_frame(AVCodecContext *avctx,
             }
             target_packet_size =
             source_packet_size = elements * 2;
+            planar = 0;
             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "Unsupported color depth : %d\n", bits_per_color);
@@ -173,7 +178,8 @@ static int decode_frame(AVCodecContext *avctx,
     // Move pointer to offset from start of file
     buf =  avpkt->data + offset;
 
-    ptr    = p->data[0];
+    for (i=0; i<AV_NUM_DATA_POINTERS; i++)
+        ptr[i] = p->data[i];
     stride = p->linesize[0];
 
     if (source_packet_size*avctx->width*avctx->height > buf_end - buf) {
@@ -183,35 +189,56 @@ static int decode_frame(AVCodecContext *avctx,
     switch (bits_per_color) {
         case 10:
             for (x = 0; x < avctx->height; x++) {
-               uint16_t *dst = (uint16_t*)ptr;
+                uint16_t *dst[3] = {(uint16_t*)ptr[0],
+                                    (uint16_t*)ptr[1],
+                                    (uint16_t*)ptr[2]};
                for (y = 0; y < avctx->width; y++) {
                    rgbBuffer = read32(&buf, endian);
-                   // Read out the 10-bit colors and convert to 16-bit
-                   *dst++ = make_16bit(rgbBuffer >> 16);
-                   *dst++ = make_16bit(rgbBuffer >>  6);
-                   *dst++ = make_16bit(rgbBuffer <<  4);
+                   *dst[0]++ = (rgbBuffer >> 12) & 0x3FF;
+                   *dst[1]++ = (rgbBuffer >> 2)  & 0x3FF;
+                   *dst[2]++ = (rgbBuffer >> 22) & 0x3FF;
                }
-               ptr += stride;
+               for (i=0; i<3; i++)
+                   ptr[i] += p->linesize[i];
             }
             break;
         case 8:
-        case 12: // Treat 12-bit as 16-bit
+        case 12:
         case 16:
-            if (source_packet_size == target_packet_size) {
+            if (planar) {
+                int source_bpc = target_packet_size / elements;
+                int target_bpc = target_packet_size / elements;
                 for (x = 0; x < avctx->height; x++) {
-                    memcpy(ptr, buf, target_packet_size*avctx->width);
-                    ptr += stride;
-                    buf += source_packet_size*avctx->width;
+                    uint8_t *dst[AV_NUM_DATA_POINTERS];
+                    for (i=0; i<elements; i++)
+                        dst[i] = ptr[i];
+                    for (y = 0; y < avctx->width; y++) {
+                        for (i=0; i<3; i++) {
+                            memcpy(dst[i], buf, FFMIN(source_bpc, target_bpc));
+                            dst[i] += target_bpc;
+                            buf += source_bpc;
+                        }
+                    }
+                    for (i=0; i<elements; i++)
+                        ptr[i] += p->linesize[i];
                 }
             } else {
-                for (x = 0; x < avctx->height; x++) {
-                    uint8_t *dst = ptr;
-                    for (y = 0; y < avctx->width; y++) {
-                        memcpy(dst, buf, target_packet_size);
-                        dst += target_packet_size;
-                        buf += source_packet_size;
+                if (source_packet_size == target_packet_size) {
+                    for (x = 0; x < avctx->height; x++) {
+                        memcpy(ptr[0], buf, target_packet_size*avctx->width);
+                        ptr[0] += stride;
+                        buf += source_packet_size*avctx->width;
+                    }
+                } else {
+                    for (x = 0; x < avctx->height; x++) {
+                        uint8_t *dst = ptr[0];
+                        for (y = 0; y < avctx->width; y++) {
+                            memcpy(dst, buf, target_packet_size);
+                            dst += target_packet_size;
+                            buf += source_packet_size;
+                        }
+                        ptr[0] += stride;
                     }
-                    ptr += stride;
                 }
             }
             break;
-- 
1.7.3.4