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/libavcodec/eatgv.c

http://github.com/FFmpeg/FFmpeg
C | 372 lines | 276 code | 53 blank | 43 comment | 64 complexity | db20c9db432189629e0ee9dcd1fb4284 MD5 | raw file
  1/*
  2 * Electronic Arts TGV 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 TGV Video Decoder
 25 * by Peter Ross (pross@xvid.org)
 26 *
 27 * Technical details here:
 28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV
 29 */
 30
 31#include "libavutil/imgutils.h"
 32#include "libavutil/mem.h"
 33
 34#define BITSTREAM_READER_LE
 35#include "avcodec.h"
 36#include "get_bits.h"
 37#include "internal.h"
 38
 39#define EA_PREAMBLE_SIZE    8
 40#define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
 41
 42typedef struct TgvContext {
 43    AVCodecContext *avctx;
 44    AVFrame *last_frame;
 45    uint8_t *frame_buffer;
 46    int width,height;
 47    uint32_t palette[AVPALETTE_COUNT];
 48
 49    int (*mv_codebook)[2];
 50    uint8_t (*block_codebook)[16];
 51    int num_mvs;           ///< current length of mv_codebook
 52    int num_blocks_packed; ///< current length of block_codebook
 53} TgvContext;
 54
 55static av_cold int tgv_decode_init(AVCodecContext *avctx)
 56{
 57    TgvContext *s = avctx->priv_data;
 58    s->avctx         = avctx;
 59    avctx->framerate = (AVRational){ 15, 1 };
 60    avctx->pix_fmt   = AV_PIX_FMT_PAL8;
 61
 62    s->last_frame = av_frame_alloc();
 63    if (!s->last_frame)
 64        return AVERROR(ENOMEM);
 65
 66    return 0;
 67}
 68
 69/**
 70 * Unpack buffer
 71 * @return 0 on success, -1 on critical buffer underflow
 72 */
 73static int unpack(const uint8_t *src, const uint8_t *src_end,
 74                  uint8_t *dst, int width, int height)
 75{
 76    uint8_t *dst_end = dst + width*height;
 77    int size, size1, size2, offset, run;
 78    uint8_t *dst_start = dst;
 79
 80    if (src[0] & 0x01)
 81        src += 5;
 82    else
 83        src += 2;
 84
 85    if (src_end - src < 3)
 86        return AVERROR_INVALIDDATA;
 87    size = AV_RB24(src);
 88    src += 3;
 89
 90    while (size > 0 && src < src_end) {
 91
 92        /* determine size1 and size2 */
 93        size1 = (src[0] & 3);
 94        if (src[0] & 0x80) {  // 1
 95            if (src[0] & 0x40 ) {  // 11
 96                if (src[0] & 0x20) {  // 111
 97                    if (src[0] < 0xFC)  // !(111111)
 98                        size1 = (((src[0] & 31) + 1) << 2);
 99                    src++;
100                    size2 = 0;
101                } else {  // 110
102                    offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;
103                    size2  = ((src[0] & 0xC) << 6) + src[3] + 5;
104                    src   += 4;
105                }
106            } else {  // 10
107                size1  = ((src[1] & 0xC0) >> 6);
108                offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;
109                size2  = (src[0] & 0x3F) + 4;
110                src   += 3;
111            }
112        } else {  // 0
113            offset = ((src[0] & 0x60) << 3) + src[1] + 1;
114            size2  = ((src[0] & 0x1C) >> 2) + 3;
115            src   += 2;
116        }
117
118
119        /* fetch strip from src */
120        if (size1 > src_end - src)
121            break;
122
123        if (size1 > 0) {
124            size -= size1;
125            run   = FFMIN(size1, dst_end - dst);
126            memcpy(dst, src, run);
127            dst += run;
128            src += run;
129        }
130
131        if (size2 > 0) {
132            if (dst - dst_start < offset)
133                return 0;
134            size -= size2;
135            run   = FFMIN(size2, dst_end - dst);
136            av_memcpy_backptr(dst, offset, run);
137            dst += run;
138        }
139    }
140
141    return 0;
142}
143
144/**
145 * Decode inter-frame
146 * @return 0 on success, -1 on critical buffer underflow
147 */
148static int tgv_decode_inter(TgvContext *s, AVFrame *frame,
149                            const uint8_t *buf, const uint8_t *buf_end)
150{
151    int num_mvs;
152    int num_blocks_raw;
153    int num_blocks_packed;
154    int vector_bits;
155    int i,j,x,y;
156    GetBitContext gb;
157    int mvbits;
158    const uint8_t *blocks_raw;
159
160    if(buf_end - buf < 12)
161        return AVERROR_INVALIDDATA;
162
163    num_mvs           = AV_RL16(&buf[0]);
164    num_blocks_raw    = AV_RL16(&buf[2]);
165    num_blocks_packed = AV_RL16(&buf[4]);
166    vector_bits       = AV_RL16(&buf[6]);
167    buf += 12;
168
169    if (vector_bits > MIN_CACHE_BITS || !vector_bits) {
170        av_log(s->avctx, AV_LOG_ERROR,
171               "Invalid value for motion vector bits: %d\n", vector_bits);
172        return AVERROR_INVALIDDATA;
173    }
174
175    /* allocate codebook buffers as necessary */
176    if (num_mvs > s->num_mvs) {
177        int err = av_reallocp_array(&s->mv_codebook, num_mvs, sizeof(*s->mv_codebook));
178        if (err < 0) {
179            s->num_mvs = 0;
180            return err;
181        }
182        s->num_mvs = num_mvs;
183    }
184
185    if (num_blocks_packed > s->num_blocks_packed) {
186        int err;
187        if ((err = av_reallocp(&s->block_codebook, num_blocks_packed * 16)) < 0) {
188            s->num_blocks_packed = 0;
189            return err;
190        }
191        s->num_blocks_packed = num_blocks_packed;
192    }
193
194    /* read motion vectors */
195    mvbits = (num_mvs * 2 * 10 + 31) & ~31;
196
197    if (buf_end - buf < (mvbits>>3) + 16*num_blocks_raw + 8*num_blocks_packed)
198        return AVERROR_INVALIDDATA;
199
200    init_get_bits(&gb, buf, mvbits);
201    for (i = 0; i < num_mvs; i++) {
202        s->mv_codebook[i][0] = get_sbits(&gb, 10);
203        s->mv_codebook[i][1] = get_sbits(&gb, 10);
204    }
205    buf += mvbits >> 3;
206
207    /* note ptr to uncompressed blocks */
208    blocks_raw = buf;
209    buf       += num_blocks_raw * 16;
210
211    /* read compressed blocks */
212    init_get_bits(&gb, buf, (buf_end - buf) << 3);
213    for (i = 0; i < num_blocks_packed; i++) {
214        int tmp[4];
215        for (j = 0; j < 4; j++)
216            tmp[j] = get_bits(&gb, 8);
217        for (j = 0; j < 16; j++)
218            s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)];
219    }
220
221    if (get_bits_left(&gb) < vector_bits *
222        (s->avctx->height / 4) * (s->avctx->width / 4))
223        return AVERROR_INVALIDDATA;
224
225    /* read vectors and build frame */
226    for (y = 0; y < s->avctx->height / 4; y++)
227        for (x = 0; x < s->avctx->width / 4; x++) {
228            unsigned int vector = get_bits(&gb, vector_bits);
229            const uint8_t *src;
230            ptrdiff_t src_stride;
231
232            if (vector < num_mvs) {
233                int mx = x * 4 + s->mv_codebook[vector][0];
234                int my = y * 4 + s->mv_codebook[vector][1];
235
236                if (mx < 0 || mx + 4 > s->avctx->width ||
237                    my < 0 || my + 4 > s->avctx->height) {
238                    av_log(s->avctx, AV_LOG_ERROR, "MV %d %d out of picture\n", mx, my);
239                    continue;
240                }
241
242                src = s->last_frame->data[0] + mx + my * s->last_frame->linesize[0];
243                src_stride = s->last_frame->linesize[0];
244            } else {
245                int offset = vector - num_mvs;
246                if (offset < num_blocks_raw)
247                    src = blocks_raw + 16*offset;
248                else if (offset - num_blocks_raw < num_blocks_packed)
249                    src = s->block_codebook[offset - num_blocks_raw];
250                else
251                    continue;
252                src_stride = 4;
253            }
254
255            for (j = 0; j < 4; j++)
256                for (i = 0; i < 4; i++)
257                    frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] =
258                        src[j * src_stride + i];
259    }
260
261    return 0;
262}
263
264static int tgv_decode_frame(AVCodecContext *avctx,
265                            void *data, int *got_frame,
266                            AVPacket *avpkt)
267{
268    const uint8_t *buf     = avpkt->data;
269    int buf_size           = avpkt->size;
270    TgvContext *s          = avctx->priv_data;
271    const uint8_t *buf_end = buf + buf_size;
272    AVFrame *frame         = data;
273    int chunk_type, ret;
274
275    if (buf_end - buf < EA_PREAMBLE_SIZE)
276        return AVERROR_INVALIDDATA;
277
278    chunk_type = AV_RL32(&buf[0]);
279    buf       += EA_PREAMBLE_SIZE;
280
281    if (chunk_type == kVGT_TAG) {
282        int pal_count, i;
283        if(buf_end - buf < 12) {
284            av_log(avctx, AV_LOG_WARNING, "truncated header\n");
285            return AVERROR_INVALIDDATA;
286        }
287
288        s->width  = AV_RL16(&buf[0]);
289        s->height = AV_RL16(&buf[2]);
290        if (s->avctx->width != s->width || s->avctx->height != s->height) {
291            av_freep(&s->frame_buffer);
292            av_frame_unref(s->last_frame);
293            if ((ret = ff_set_dimensions(s->avctx, s->width, s->height)) < 0)
294                return ret;
295        }
296
297        pal_count = AV_RL16(&buf[6]);
298        buf += 12;
299        for(i = 0; i < pal_count && i < AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
300            s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
301            buf += 3;
302        }
303        if (buf_end - buf < 5) {
304            return AVERROR_INVALIDDATA;
305        }
306    }
307
308    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
309        return ret;
310
311    memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
312
313    if (chunk_type == kVGT_TAG) {
314        int y;
315        frame->key_frame = 1;
316        frame->pict_type = AV_PICTURE_TYPE_I;
317
318        if (!s->frame_buffer &&
319            !(s->frame_buffer = av_mallocz(s->width * s->height)))
320            return AVERROR(ENOMEM);
321
322        if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) {
323            av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
324            return AVERROR_INVALIDDATA;
325        }
326        for (y = 0; y < s->height; y++)
327            memcpy(frame->data[0]  + y * frame->linesize[0],
328                   s->frame_buffer + y * s->width,
329                   s->width);
330    } else {
331        if (!s->last_frame->data[0]) {
332            av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
333            return buf_size;
334        }
335        frame->key_frame = 0;
336        frame->pict_type = AV_PICTURE_TYPE_P;
337        if (tgv_decode_inter(s, frame, buf, buf_end) < 0) {
338            av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
339            return AVERROR_INVALIDDATA;
340        }
341    }
342
343    av_frame_unref(s->last_frame);
344    if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
345        return ret;
346
347    *got_frame = 1;
348
349    return buf_size;
350}
351
352static av_cold int tgv_decode_end(AVCodecContext *avctx)
353{
354    TgvContext *s = avctx->priv_data;
355    av_frame_free(&s->last_frame);
356    av_freep(&s->frame_buffer);
357    av_freep(&s->mv_codebook);
358    av_freep(&s->block_codebook);
359    return 0;
360}
361
362AVCodec ff_eatgv_decoder = {
363    .name           = "eatgv",
364    .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"),
365    .type           = AVMEDIA_TYPE_VIDEO,
366    .id             = AV_CODEC_ID_TGV,
367    .priv_data_size = sizeof(TgvContext),
368    .init           = tgv_decode_init,
369    .close          = tgv_decode_end,
370    .decode         = tgv_decode_frame,
371    .capabilities   = AV_CODEC_CAP_DR1,
372};