DPX (Digital Picture Exchange) image decoder

patch by Jimmy Christensen, jimmy ghost dk

Originally committed as revision 19163 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 228 insertions, 0 deletions

diff --git a/libavcodec/dpx.c b/libavcodec/dpx.c
new file mode 100644
index 0000000000..fec12f94ca
--- /dev/null
+++ b/libavcodec/dpx.c
@@ -0,0 +1,228 @@
+/*
+ * DPX (.dpx) image decoder
+ * Copyright (c) 2009 Jimmy Christensen
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "bytestream.h"
+#include "avcodec.h"
+
+typedef struct DPXContext {
+    AVFrame picture;
+} DPXContext;
+
+
+static unsigned int read32(const uint8_t **ptr, int is_big)
+{
+    unsigned int temp;
+    if (is_big) {
+        temp = AV_RB32(*ptr);
+    } else {
+        temp = AV_RL32(*ptr);
+    }
+    *ptr += 4;
+    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,
+                        AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size       = avpkt->size;
+    DPXContext *const s = avctx->priv_data;
+    AVFrame *picture  = data;
+    AVFrame *const p = &s->picture;
+    uint8_t *ptr;
+
+    int magic_num, offset, endian;
+    int x, y;
+    int w, h, stride, bits_per_color, descriptor, elements, target_packet_size, source_packet_size;
+
+    unsigned int rgbBuffer;
+
+    magic_num = AV_RB32(buf);
+    buf += 4;
+
+    /* Check if the files "magic number" is "SDPX" which means it uses
+     * big-endian or XPDS which is for little-endian files */
+    if (magic_num == AV_RL32("SDPX")) {
+        endian = 0;
+    } else if (magic_num == AV_RB32("SDPX")) {
+        endian = 1;
+    } else {
+        av_log(avctx, AV_LOG_ERROR, "DPX marker not found\n");
+        return -1;
+    }
+
+    offset = read32(&buf, endian);
+    // Need to end in 0x304 offset from start of file
+    buf = avpkt->data + 0x304;
+    w = read32(&buf, endian);
+    h = read32(&buf, endian);
+
+    // Need to end in 0x320 to read the descriptor
+    buf += 20;
+    descriptor = buf[0];
+
+    // Need to end in 0x323 to read the bits per color
+    buf += 3;
+    bits_per_color = buf[0];
+
+    switch (descriptor) {
+        case 51: // RGBA
+            elements = 4;
+            break;
+        case 50: // RGB
+            elements = 3;
+            break;
+        default:
+            av_log(avctx, AV_LOG_ERROR, "Unsupported descriptor %d\n", descriptor);
+            return -1;
+    }
+
+    switch (bits_per_color) {
+        case 8:
+            if (elements == 4) {
+                avctx->pix_fmt = PIX_FMT_RGBA;
+            } else {
+                avctx->pix_fmt = PIX_FMT_RGB24;
+            }
+            source_packet_size = elements;
+            target_packet_size = elements;
+            break;
+        case 10:
+            avctx->pix_fmt = PIX_FMT_RGB48;
+            target_packet_size = 6;
+            source_packet_size = elements * 2;
+            break;
+        case 12:
+        case 16:
+            if (endian) {
+                avctx->pix_fmt = PIX_FMT_RGB48BE;
+            } else {
+                avctx->pix_fmt = PIX_FMT_RGB48LE;
+            }
+            target_packet_size = 6;
+            source_packet_size = elements * 2;
+            break;
+        default:
+            av_log(avctx, AV_LOG_ERROR, "Unsupported color depth : %d\n", bits_per_color);
+            return -1;
+    }
+
+    if (s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+    if (avcodec_check_dimensions(avctx, w, h))
+        return -1;
+    if (w != avctx->width || h != avctx->height)
+        avcodec_set_dimensions(avctx, w, h);
+    if (avctx->get_buffer(avctx, p) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+
+    // Move pointer to offset from start of file
+    buf =  avpkt->data + offset;
+
+    ptr    = p->data[0];
+    stride = p->linesize[0];
+
+    switch (bits_per_color) {
+        case 10:
+            for (x = 0; x < avctx->height; x++) {
+               uint16_t *dst = (uint16_t*)ptr;
+               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);
+               }
+               ptr += stride;
+            }
+            break;
+        case 8:
+        case 12: // Treat 12-bit as 16-bit
+        case 16:
+            if (source_packet_size == target_packet_size) {
+                for (x = 0; x < avctx->height; x++) {
+                    memcpy(ptr, buf, target_packet_size*avctx->width);
+                    ptr += stride;
+                    buf += source_packet_size*avctx->width;
+                }
+            } 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;
+                    }
+                    ptr += stride;
+                }
+            }
+            break;
+    }
+
+    *picture   = s->picture;
+    *data_size = sizeof(AVPicture);
+
+    return buf_size;
+}
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    DPXContext *s = avctx->priv_data;
+    avcodec_get_frame_defaults(&s->picture);
+    avctx->coded_frame = &s->picture;
+    return 0;
+}
+
+static av_cold int decode_end(AVCodecContext *avctx)
+{
+    DPXContext *s = avctx->priv_data;
+    if (s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+
+    return 0;
+}
+
+AVCodec dpx_decoder = {
+    "dpx",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_DPX,
+    sizeof(DPXContext),
+    decode_init,
+    NULL,
+    decode_end,
+    decode_frame,
+    0,
+    NULL,
+    .long_name = NULL_IF_CONFIG_SMALL("DPX image"),
+};