Electronic Arts CMV decoder

Originally committed as revision 14110 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 214 insertions, 0 deletions

diff --git a/libavcodec/eacmv.c b/libavcodec/eacmv.c
new file mode 100644
index 0000000000..a9f624e046
--- /dev/null
+++ b/libavcodec/eacmv.c
@@ -0,0 +1,214 @@
+/*
+ * Electronic Arts CMV Video Decoder
+ * Copyright (c) 2007-2008 Peter Ross
+ *
+ * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/**
+ * @file eacmv.c
+ * Electronic Arts CMV Video Decoder
+ * by Peter Ross (suxen_drol at hotmail dot com)
+ *
+ * Technical details here:
+ * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV
+ */
+
+#include "avcodec.h"
+
+typedef struct CmvContext {
+    AVCodecContext *avctx;
+    AVFrame frame;        ///< current
+    AVFrame last_frame;   ///< last
+    AVFrame last2_frame;  ///< second-last
+    int width, height;
+    unsigned int palette[AVPALETTE_COUNT];
+} CmvContext;
+
+static av_cold int cmv_decode_init(AVCodecContext *avctx){
+    CmvContext *s = avctx->priv_data;
+    s->avctx = avctx;
+    avctx->pix_fmt = PIX_FMT_PAL8;
+    return 0;
+}
+
+static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
+    unsigned char *dst = s->frame.data[0];
+    int i;
+
+    for (i=0; i < s->avctx->height && buf+s->avctx->width<=buf_end; i++) {
+        memcpy(dst, buf, s->avctx->width);
+        dst += s->frame.linesize[0];
+        buf += s->avctx->width;
+    }
+}
+
+static void cmv_motcomp(unsigned char *dst, int dst_stride,
+                        const unsigned char *src, int src_stride,
+                        int x, int y,
+                        int xoffset, int yoffset,
+                        int width, int height){
+    int i,j;
+
+    for(j=y;j<y+4;j++)
+    for(i=x;i<x+4;i++)
+    {
+        if (i+xoffset>=0 && i+xoffset<width &&
+            j+yoffset>=0 && j+yoffset<height) {
+            dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
+        }else{
+            dst[j*dst_stride + i] = 0;
+        }
+    }
+}
+
+static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
+    const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
+    int x,y,i;
+
+    i = 0;
+    for(y=0; y<s->avctx->height/4; y++)
+    for(x=0; x<s->avctx->width/4 && buf+i<buf_end; x++) {
+        if (buf[i]==0xFF) {
+            unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4;
+            if (raw+16<buf_end && *raw==0xFF) { /* intra */
+                raw++;
+                memcpy(dst, raw, 4);
+                memcpy(dst+s->frame.linesize[0], raw+4, 4);
+                memcpy(dst+2*s->frame.linesize[0], raw+8, 4);
+                memcpy(dst+3*s->frame.linesize[0], raw+12, 4);
+                raw+=16;
+            }else if(raw<buf_end) {  /* inter using second-last frame as reference */
+                int xoffset = (*raw & 0xF) - 7;
+                int yoffset = ((*raw >> 4)) - 7;
+                cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
+                            s->last2_frame.data[0], s->last2_frame.linesize[0],
+                            x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
+                raw++;
+            }
+        }else{  /* inter using last frame as reference */
+            int xoffset = (buf[i] & 0xF) - 7;
+            int yoffset = ((buf[i] >> 4)) - 7;
+            cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
+                      s->last_frame.data[0], s->last_frame.linesize[0],
+                      x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
+        }
+        i++;
+    }
+}
+
+static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
+{
+    int pal_start, pal_count, i;
+
+    if(buf+16>=buf_end) {
+        av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
+        return;
+    }
+
+    s->width  = AV_RL16(&buf[4]);
+    s->height = AV_RL16(&buf[6]);
+    if (s->avctx->width!=s->width || s->avctx->height!=s->height)
+        avcodec_set_dimensions(s->avctx, s->width, s->height);
+
+    s->avctx->time_base.num = 1;
+    s->avctx->time_base.den = AV_RL16(&buf[10]);
+
+    pal_start = AV_RL16(&buf[12]);
+    pal_count = AV_RL16(&buf[14]);
+
+    buf += 16;
+    for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) {
+        s->palette[i] = AV_RB24(buf);
+        buf += 3;
+    }
+}
+
+#define EA_PREAMBLE_SIZE 8
+#define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
+
+static int cmv_decode_frame(AVCodecContext *avctx,
+                            void *data, int *data_size,
+                            const uint8_t *buf, int buf_size)
+{
+    CmvContext *s = avctx->priv_data;
+    const uint8_t *buf_end = buf + buf_size;
+
+    if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
+        cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
+        return buf_size;
+    }
+
+    if (avcodec_check_dimensions(s->avctx, s->width, s->height))
+        return -1;
+
+    /* shuffle */
+    if (s->last2_frame.data[0])
+        avctx->release_buffer(avctx, &s->last2_frame);
+    FFSWAP(AVFrame, s->last_frame, s->last2_frame);
+    FFSWAP(AVFrame, s->frame, s->last_frame);
+
+    s->frame.reference = 1;
+    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
+    if (avctx->get_buffer(avctx, &s->frame)<0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+
+    memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
+
+    buf += EA_PREAMBLE_SIZE;
+    if ((buf[0]&1)) {  // subtype
+        cmv_decode_inter(s, buf+2, buf_end);
+        s->frame.key_frame = 0;
+        s->frame.pict_type = FF_P_TYPE;
+    }else{
+        s->frame.key_frame = 1;
+        s->frame.pict_type = FF_I_TYPE;
+        cmv_decode_intra(s, buf+2, buf_end);
+    }
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = s->frame;
+
+    return buf_size;
+}
+
+static av_cold int cmv_decode_end(AVCodecContext *avctx){
+    CmvContext *s = avctx->priv_data;
+    if (s->frame.data[0])
+        s->avctx->release_buffer(avctx, &s->frame);
+    if (s->last_frame.data[0])
+        s->avctx->release_buffer(avctx, &s->last_frame);
+    if (s->last2_frame.data[0])
+        s->avctx->release_buffer(avctx, &s->last2_frame);
+
+    return 0;
+}
+
+AVCodec eacmv_decoder = {
+    "eacmv",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_CMV,
+    sizeof(CmvContext),
+    cmv_decode_init,
+    NULL,
+    cmv_decode_end,
+    cmv_decode_frame,
+    CODEC_CAP_DR1,
+    .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV Video"),
+};