1/*
2 * Electronic Arts CMV Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
20 */
21
22/**
23 * @file
24 * Electronic Arts CMV Video Decoder
25 * by Peter Ross (pross@xvid.org)
26 *
27 * Technical details here:
28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV
29 */
30
31#include "libavutil/common.h"
32#include "libavutil/intreadwrite.h"
33#include "libavutil/imgutils.h"
34#include "avcodec.h"
35#include "internal.h"
36
37typedef struct CmvContext {
38    AVCodecContext *avctx;
39    AVFrame *last_frame;   ///< last
40    AVFrame *last2_frame;  ///< second-last
41    int width, height;
42    unsigned int palette[AVPALETTE_COUNT];
43} CmvContext;
44
45static av_cold int cmv_decode_init(AVCodecContext *avctx){
46    CmvContext *s = avctx->priv_data;
47
48    s->avctx = avctx;
49    avctx->pix_fmt = AV_PIX_FMT_PAL8;
50
51    s->last_frame  = av_frame_alloc();
52    s->last2_frame = av_frame_alloc();
53    if (!s->last_frame || !s->last2_frame) {
54        av_frame_free(&s->last_frame);
55        av_frame_free(&s->last2_frame);
56        return AVERROR(ENOMEM);
57    }
58
59    return 0;
60}
61
62static void cmv_decode_intra(CmvContext * s, AVFrame *frame,
63                             const uint8_t *buf, const uint8_t *buf_end)
64{
65    unsigned char *dst = frame->data[0];
66    int i;
67
68    for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
69        memcpy(dst, buf, s->avctx->width);
70        dst += frame->linesize[0];
71        buf += s->avctx->width;
72    }
73}
74
75static void cmv_motcomp(unsigned char *dst, int dst_stride,
76                        const unsigned char *src, int src_stride,
77                        int x, int y,
78                        int xoffset, int yoffset,
79                        int width, int height){
80    int i,j;
81
82    for(j=y;j<y+4;j++)
83    for(i=x;i<x+4;i++)
84    {
85        if (i+xoffset>=0 && i+xoffset<width &&
86            j+yoffset>=0 && j+yoffset<height) {
87            dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
88        }else{
89            dst[j*dst_stride + i] = 0;
90        }
91    }
92}
93
94static void cmv_decode_inter(CmvContext *s, AVFrame *frame, const uint8_t *buf,
95                             const uint8_t *buf_end)
96{
97    const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
98    int x,y,i;
99
100    i = 0;
101    for(y=0; y<s->avctx->height/4; y++)
102    for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
103        if (buf[i]==0xFF) {
104            unsigned char *dst = frame->data[0] + (y*4)*frame->linesize[0] + x*4;
105            if (raw+16<buf_end && *raw==0xFF) { /* intra */
106                raw++;
107                memcpy(dst, raw, 4);
108                memcpy(dst +     frame->linesize[0], raw+4, 4);
109                memcpy(dst + 2 * frame->linesize[0], raw+8, 4);
110                memcpy(dst + 3 * frame->linesize[0], raw+12, 4);
111                raw+=16;
112            }else if(raw<buf_end) {  /* inter using second-last frame as reference */
113                int xoffset = (*raw & 0xF) - 7;
114                int yoffset = ((*raw >> 4)) - 7;
115                if (s->last2_frame->data[0])
116                    cmv_motcomp(frame->data[0], frame->linesize[0],
117                                s->last2_frame->data[0], s->last2_frame->linesize[0],
118                                x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
119                raw++;
120            }
121        }else{  /* inter using last frame as reference */
122            int xoffset = (buf[i] & 0xF) - 7;
123            int yoffset = ((buf[i] >> 4)) - 7;
124            if (s->last_frame->data[0])
125                cmv_motcomp(frame->data[0], frame->linesize[0],
126                            s->last_frame->data[0], s->last_frame->linesize[0],
127                            x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
128        }
129        i++;
130    }
131}
132
133static int cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
134{
135    int pal_start, pal_count, i, ret, fps;
136
137    if(buf_end - buf < 16) {
138        av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
139        return AVERROR_INVALIDDATA;
140    }
141
142    s->width  = AV_RL16(&buf[4]);
143    s->height = AV_RL16(&buf[6]);
144
145    if (s->width  != s->avctx->width ||
146        s->height != s->avctx->height) {
147        av_frame_unref(s->last_frame);
148        av_frame_unref(s->last2_frame);
149    }
150
151    ret = ff_set_dimensions(s->avctx, s->width, s->height);
152    if (ret < 0)
153        return ret;
154
155    fps = AV_RL16(&buf[10]);
156    if (fps > 0)
157        s->avctx->time_base = (AVRational){ 1, fps };
158
159    pal_start = AV_RL16(&buf[12]);
160    pal_count = AV_RL16(&buf[14]);
161
162    buf += 16;
163    for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
164        s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
165        buf += 3;
166    }
167
168    return 0;
169}
170
171#define EA_PREAMBLE_SIZE 8
172#define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
173
174static int cmv_decode_frame(AVCodecContext *avctx,
175                            void *data, int *got_frame,
176                            AVPacket *avpkt)
177{
178    const uint8_t *buf = avpkt->data;
179    int buf_size = avpkt->size;
180    CmvContext *s = avctx->priv_data;
181    const uint8_t *buf_end = buf + buf_size;
182    AVFrame *frame = data;
183    int ret;
184
185    if (buf_end - buf < EA_PREAMBLE_SIZE)
186        return AVERROR_INVALIDDATA;
187
188    if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
189        unsigned size = AV_RL32(buf + 4);
190        ret = cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
191        if (ret < 0)
192            return ret;
193        if (size > buf_end - buf - EA_PREAMBLE_SIZE)
194            return -1;
195        buf += size;
196    }
197
198    if (av_image_check_size(s->width, s->height, 0, s->avctx))
199        return -1;
200
201    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
202        return ret;
203
204    memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
205
206    buf += EA_PREAMBLE_SIZE;
207    if ((buf[0]&1)) {  // subtype
208        cmv_decode_inter(s, frame, buf+2, buf_end);
209        frame->key_frame = 0;
210        frame->pict_type = AV_PICTURE_TYPE_P;
211    }else{
212        frame->key_frame = 1;
213        frame->pict_type = AV_PICTURE_TYPE_I;
214        cmv_decode_intra(s, frame, buf+2, buf_end);
215    }
216
217    av_frame_unref(s->last2_frame);
218    av_frame_move_ref(s->last2_frame, s->last_frame);
219    if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
220        return ret;
221
222    *got_frame = 1;
223
224    return buf_size;
225}
226
227static av_cold int cmv_decode_end(AVCodecContext *avctx){
228    CmvContext *s = avctx->priv_data;
229
230    av_frame_free(&s->last_frame);
231    av_frame_free(&s->last2_frame);
232
233    return 0;
234}
235
236AVCodec ff_eacmv_decoder = {
237    .name           = "eacmv",
238    .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),
239    .type           = AVMEDIA_TYPE_VIDEO,
240    .id             = AV_CODEC_ID_CMV,
241    .priv_data_size = sizeof(CmvContext),
242    .init           = cmv_decode_init,
243    .close          = cmv_decode_end,
244    .decode         = cmv_decode_frame,
245    .capabilities   = CODEC_CAP_DR1,
246};
247