[FFmpeg-devel] [PATCH 2/2] avcodec/dpx: improve decoding support for 10 bit depth

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavcodec/dpx.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/libavcodec/dpx.c b/libavcodec/dpx.c
index 0297287938..84894abda5 100644
--- a/libavcodec/dpx.c
+++ b/libavcodec/dpx.c
@@ -50,6 +50,24 @@ static unsigned int read32(const uint8_t **ptr, int is_big)
     return temp;
 }
 
+static uint16_t read10in32_gray(const uint8_t **ptr, uint32_t *lbuf,
+                                int *n_datum, int is_big, int shift)
+{
+    uint16_t temp;
+
+    if (*n_datum)
+        (*n_datum)--;
+    else {
+        *lbuf = read32(ptr, is_big);
+        *n_datum = 2;
+    }
+
+    temp = *lbuf >> shift & 0x3FF;
+    *lbuf = *lbuf >> 10;
+
+    return temp;
+}
+
 static uint16_t read10in32(const uint8_t **ptr, uint32_t * lbuf,
                                   int * n_datum, int is_big, int shift)
 {
@@ -107,6 +125,7 @@ static int decode_frame(AVCodecContext *avctx,
     AVFrame *const p = data;
     uint8_t *ptr[AV_NUM_DATA_POINTERS];
     uint32_t header_version, version = 0;
+    const uint8_t *creator;
 
     unsigned int offset;
     int magic_num, endian;
@@ -151,6 +170,9 @@ static int decode_frame(AVCodecContext *avctx,
         av_log(avctx, AV_LOG_WARNING, "Unknown header format version %s.\n",
                av_fourcc2str(header_version));
 
+    buf = avpkt->data + 160;
+    creator = buf;
+
     // Check encryption
     buf = avpkt->data + 660;
     ret = read32(&buf, endian);
@@ -320,6 +342,7 @@ static int decode_frame(AVCodecContext *avctx,
     case 51121:
         avctx->pix_fmt = AV_PIX_FMT_GBRAP12;
         break;
+    case 6100:
     case 6101:
         avctx->pix_fmt = AV_PIX_FMT_GRAY10;
         break;
@@ -373,13 +396,17 @@ static int decode_frame(AVCodecContext *avctx,
                                 (uint16_t*)ptr[1],
                                 (uint16_t*)ptr[2],
                                 (uint16_t*)ptr[3]};
-            int shift = packing == 1 ? 22 : 20;
+            int shift = elements > 1 ? packing == 1 ? 22 : 20 : packing == 1 ? 2 : 0;
             for (y = 0; y < avctx->width; y++) {
                 if (elements >= 3)
                     *dst[2]++ = read10in32(&buf, &rgbBuffer,
                                            &n_datum, endian, shift);
-                *dst[0]++ = read10in32(&buf, &rgbBuffer,
-                                       &n_datum, endian, shift);
+                if (elements == 1)
+                    *dst[0]++ = read10in32_gray(&buf, &rgbBuffer,
+                                                &n_datum, endian, shift);
+                else
+                    *dst[0]++ = read10in32(&buf, &rgbBuffer,
+                                           &n_datum, endian, shift);
                 if (elements >= 2)
                     *dst[1]++ = read10in32(&buf, &rgbBuffer,
                                            &n_datum, endian, shift);
@@ -388,7 +415,8 @@ static int decode_frame(AVCodecContext *avctx,
                     read10in32(&buf, &rgbBuffer,
                                &n_datum, endian, shift);
             }
-            n_datum = 0;
+            if (version != 2 || !memcmp(creator, "GraphicsMagick", 14))
+                n_datum = 0;
             for (i = 0; i < elements; i++)
                 ptr[i] += p->linesize[i];
         }
-- 
2.17.1