FFmpeg: libavcodec/dfa.c Source File

00001 /*
00002  * Chronomaster DFA Video Decoder
00003  * Copyright (c) 2011 Konstantin Shishkov
00004  * based on work by Vladimir "VAG" Gneushev
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "avcodec.h"
00024 #include "bytestream.h"
00025 
00026 #include "libavutil/imgutils.h"
00027 #include "libavutil/lzo.h" // for av_memcpy_backptr
00028 
00029 typedef struct DfaContext {
00030     AVFrame pic;
00031 
00032     uint32_t pal[256];
00033     uint8_t *frame_buf;
00034 } DfaContext;
00035 
00036 static av_cold int dfa_decode_init(AVCodecContext *avctx)
00037 {
00038     DfaContext *s = avctx->priv_data;
00039     int ret;
00040 
00041     avctx->pix_fmt = PIX_FMT_PAL8;
00042 
00043     if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
00044         return ret;
00045 
00046     s->frame_buf = av_mallocz(avctx->width * avctx->height + AV_LZO_OUTPUT_PADDING);
00047     if (!s->frame_buf)
00048         return AVERROR(ENOMEM);
00049 
00050     return 0;
00051 }
00052 
00053 static int decode_copy(GetByteContext *gb, uint8_t *frame, int width, int height)
00054 {
00055     const int size = width * height;
00056 
00057     if (bytestream2_get_buffer(gb, frame, size) != size)
00058         return AVERROR_INVALIDDATA;
00059     return 0;
00060 }
00061 
00062 static int decode_tsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
00063 {
00064     const uint8_t *frame_start = frame;
00065     const uint8_t *frame_end   = frame + width * height;
00066     int mask = 0x10000, bitbuf = 0;
00067     int v, count, segments;
00068     unsigned offset;
00069 
00070     segments = bytestream2_get_le32(gb);
00071     offset   = bytestream2_get_le32(gb);
00072     if (frame_end - frame <= offset)
00073         return AVERROR_INVALIDDATA;
00074     frame += offset;
00075     while (segments--) {
00076         if (bytestream2_get_bytes_left(gb) < 2)
00077             return AVERROR_INVALIDDATA;
00078         if (mask == 0x10000) {
00079             bitbuf = bytestream2_get_le16u(gb);
00080             mask = 1;
00081         }
00082         if (frame_end - frame < 2)
00083             return AVERROR_INVALIDDATA;
00084         if (bitbuf & mask) {
00085             v = bytestream2_get_le16(gb);
00086             offset = (v & 0x1FFF) << 1;
00087             count = ((v >> 13) + 2) << 1;
00088             if (frame - frame_start < offset || frame_end - frame < count)
00089                 return AVERROR_INVALIDDATA;
00090             av_memcpy_backptr(frame, offset, count);
00091             frame += count;
00092         } else {
00093             *frame++ = bytestream2_get_byte(gb);
00094             *frame++ = bytestream2_get_byte(gb);
00095         }
00096         mask <<= 1;
00097     }
00098 
00099     return 0;
00100 }
00101 
00102 static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
00103 {
00104     const uint8_t *frame_start = frame;
00105     const uint8_t *frame_end   = frame + width * height;
00106     int mask = 0x10000, bitbuf = 0;
00107     int v, offset, count, segments;
00108 
00109     segments = bytestream2_get_le16(gb);
00110     while (segments--) {
00111         if (bytestream2_get_bytes_left(gb) < 2)
00112             return AVERROR_INVALIDDATA;
00113         if (mask == 0x10000) {
00114             bitbuf = bytestream2_get_le16u(gb);
00115             mask = 1;
00116         }
00117         if (frame_end - frame < 2)
00118             return AVERROR_INVALIDDATA;
00119         if (bitbuf & mask) {
00120             v = bytestream2_get_le16(gb);
00121             offset = (v & 0x1FFF) << 1;
00122             count = ((v >> 13) + 2) << 1;
00123             if (frame - frame_start < offset || frame_end - frame < count)
00124                 return AVERROR_INVALIDDATA;
00125             // can't use av_memcpy_backptr() since it can overwrite following pixels
00126             for (v = 0; v < count; v++)
00127                 frame[v] = frame[v - offset];
00128             frame += count;
00129         } else if (bitbuf & (mask << 1)) {
00130             frame += bytestream2_get_le16(gb);
00131         } else {
00132             *frame++ = bytestream2_get_byte(gb);
00133             *frame++ = bytestream2_get_byte(gb);
00134         }
00135         mask <<= 2;
00136     }
00137 
00138     return 0;
00139 }
00140 
00141 static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
00142 {
00143     const uint8_t *frame_start = frame;
00144     const uint8_t *frame_end   = frame + width * height;
00145     int mask = 0x10000, bitbuf = 0;
00146     int i, v, offset, count, segments;
00147 
00148     segments = bytestream2_get_le16(gb);
00149     while (segments--) {
00150         if (bytestream2_get_bytes_left(gb) < 2)
00151             return AVERROR_INVALIDDATA;
00152         if (mask == 0x10000) {
00153             bitbuf = bytestream2_get_le16u(gb);
00154             mask = 1;
00155         }
00156 
00157         if (bitbuf & mask) {
00158             v = bytestream2_get_le16(gb);
00159             offset = (v & 0x1FFF) << 2;
00160             count = ((v >> 13) + 2) << 1;
00161             if (frame - frame_start < offset || frame_end - frame < count*2 + width)
00162                 return AVERROR_INVALIDDATA;
00163             for (i = 0; i < count; i++) {
00164                 frame[0] = frame[1] =
00165                 frame[width] = frame[width + 1] = frame[-offset];
00166 
00167                 frame += 2;
00168             }
00169         } else if (bitbuf & (mask << 1)) {
00170             v = bytestream2_get_le16(gb)*2;
00171             if (frame - frame_end < v)
00172                 return AVERROR_INVALIDDATA;
00173             frame += v;
00174         } else {
00175             if (frame_end - frame < width + 3)
00176                 return AVERROR_INVALIDDATA;
00177             frame[0] = frame[1] =
00178             frame[width] = frame[width + 1] =  bytestream2_get_byte(gb);
00179             frame += 2;
00180             frame[0] = frame[1] =
00181             frame[width] = frame[width + 1] =  bytestream2_get_byte(gb);
00182             frame += 2;
00183         }
00184         mask <<= 2;
00185     }
00186 
00187     return 0;
00188 }
00189 
00190 static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
00191 {
00192     uint8_t *line_ptr;
00193     int count, lines, segments;
00194 
00195     count = bytestream2_get_le16(gb);
00196     if (count >= height)
00197         return AVERROR_INVALIDDATA;
00198     frame += width * count;
00199     lines = bytestream2_get_le16(gb);
00200     if (count + lines > height)
00201         return AVERROR_INVALIDDATA;
00202 
00203     while (lines--) {
00204         if (bytestream2_get_bytes_left(gb) < 1)
00205             return AVERROR_INVALIDDATA;
00206         line_ptr = frame;
00207         frame += width;
00208         segments = bytestream2_get_byteu(gb);
00209         while (segments--) {
00210             if (frame - line_ptr <= bytestream2_peek_byte(gb))
00211                 return AVERROR_INVALIDDATA;
00212             line_ptr += bytestream2_get_byte(gb);
00213             count = (int8_t)bytestream2_get_byte(gb);
00214             if (count >= 0) {
00215                 if (frame - line_ptr < count)
00216                     return AVERROR_INVALIDDATA;
00217                 if (bytestream2_get_buffer(gb, line_ptr, count) != count)
00218                     return AVERROR_INVALIDDATA;
00219             } else {
00220                 count = -count;
00221                 if (frame - line_ptr < count)
00222                     return AVERROR_INVALIDDATA;
00223                 memset(line_ptr, bytestream2_get_byte(gb), count);
00224             }
00225             line_ptr += count;
00226         }
00227     }
00228 
00229     return 0;
00230 }
00231 
00232 static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
00233 {
00234     const uint8_t *frame_end   = frame + width * height;
00235     uint8_t *line_ptr;
00236     int count, i, v, lines, segments;
00237     int y = 0;
00238 
00239     lines = bytestream2_get_le16(gb);
00240     if (lines > height)
00241         return AVERROR_INVALIDDATA;
00242 
00243     while (lines--) {
00244         if (bytestream2_get_bytes_left(gb) < 2)
00245             return AVERROR_INVALIDDATA;
00246         segments = bytestream2_get_le16u(gb);
00247         while ((segments & 0xC000) == 0xC000) {
00248             unsigned skip_lines = -(int16_t)segments;
00249             unsigned delta = -((int16_t)segments * width);
00250             if (frame_end - frame <= delta || y + lines + skip_lines > height)
00251                 return AVERROR_INVALIDDATA;
00252             frame    += delta;
00253             y        += skip_lines;
00254             segments = bytestream2_get_le16(gb);
00255         }
00256         if (segments & 0x8000) {
00257             frame[width - 1] = segments & 0xFF;
00258             segments = bytestream2_get_le16(gb);
00259         }
00260         line_ptr = frame;
00261         frame += width;
00262         y++;
00263         while (segments--) {
00264             if (frame - line_ptr <= bytestream2_peek_byte(gb))
00265                 return AVERROR_INVALIDDATA;
00266             line_ptr += bytestream2_get_byte(gb);
00267             count = (int8_t)bytestream2_get_byte(gb);
00268             if (count >= 0) {
00269                 if (frame - line_ptr < count * 2)
00270                     return AVERROR_INVALIDDATA;
00271                 if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
00272                     return AVERROR_INVALIDDATA;
00273                 line_ptr += count * 2;
00274             } else {
00275                 count = -count;
00276                 if (frame - line_ptr < count * 2)
00277                     return AVERROR_INVALIDDATA;
00278                 v = bytestream2_get_le16(gb);
00279                 for (i = 0; i < count; i++)
00280                     bytestream_put_le16(&line_ptr, v);
00281             }
00282         }
00283     }
00284 
00285     return 0;
00286 }
00287 
00288 static int decode_unk6(GetByteContext *gb, uint8_t *frame, int width, int height)
00289 {
00290     return AVERROR_PATCHWELCOME;
00291 }
00292 
00293 static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
00294 {
00295     memset(frame, 0, width * height);
00296     return 0;
00297 }
00298 
00299 
00300 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
00301 
00302 static const chunk_decoder decoder[8] = {
00303     decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
00304     decode_unk6, decode_dsw1, decode_blck, decode_dds1,
00305 };
00306 
00307 static const char* chunk_name[8] = {
00308     "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
00309 };
00310 
00311 static int dfa_decode_frame(AVCodecContext *avctx,
00312                             void *data, int *data_size,
00313                             AVPacket *avpkt)
00314 {
00315     DfaContext *s = avctx->priv_data;
00316     GetByteContext gb;
00317     const uint8_t *buf = avpkt->data;
00318     uint32_t chunk_type, chunk_size;
00319     uint8_t *dst;
00320     int ret;
00321     int i, pal_elems;
00322 
00323     if (s->pic.data[0])
00324         avctx->release_buffer(avctx, &s->pic);
00325 
00326     if ((ret = avctx->get_buffer(avctx, &s->pic))) {
00327         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00328         return ret;
00329     }
00330 
00331     bytestream2_init(&gb, avpkt->data, avpkt->size);
00332     while (bytestream2_get_bytes_left(&gb) > 0) {
00333         bytestream2_skip(&gb, 4);
00334         chunk_size = bytestream2_get_le32(&gb);
00335         chunk_type = bytestream2_get_le32(&gb);
00336         if (!chunk_type)
00337             break;
00338         if (chunk_type == 1) {
00339             pal_elems = FFMIN(chunk_size / 3, 256);
00340             for (i = 0; i < pal_elems; i++) {
00341                 s->pal[i] = bytestream2_get_be24(&gb) << 2;
00342                 s->pal[i] |= 0xFF << 24 | (s->pal[i] >> 6) & 0x30303;
00343             }
00344             s->pic.palette_has_changed = 1;
00345         } else if (chunk_type <= 9) {
00346             if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
00347                 av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
00348                        chunk_name[chunk_type - 2]);
00349                 return AVERROR_INVALIDDATA;
00350             }
00351         } else {
00352             av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
00353                    chunk_type);
00354         }
00355         buf += chunk_size;
00356     }
00357 
00358     buf = s->frame_buf;
00359     dst = s->pic.data[0];
00360     for (i = 0; i < avctx->height; i++) {
00361         memcpy(dst, buf, avctx->width);
00362         dst += s->pic.linesize[0];
00363         buf += avctx->width;
00364     }
00365     memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
00366 
00367     *data_size = sizeof(AVFrame);
00368     *(AVFrame*)data = s->pic;
00369 
00370     return avpkt->size;
00371 }
00372 
00373 static av_cold int dfa_decode_end(AVCodecContext *avctx)
00374 {
00375     DfaContext *s = avctx->priv_data;
00376 
00377     if (s->pic.data[0])
00378         avctx->release_buffer(avctx, &s->pic);
00379 
00380     av_freep(&s->frame_buf);
00381 
00382     return 0;
00383 }
00384 
00385 AVCodec ff_dfa_decoder = {
00386     .name           = "dfa",
00387     .type           = AVMEDIA_TYPE_VIDEO,
00388     .id             = CODEC_ID_DFA,
00389     .priv_data_size = sizeof(DfaContext),
00390     .init           = dfa_decode_init,
00391     .close          = dfa_decode_end,
00392     .decode         = dfa_decode_frame,
00393     .capabilities   = CODEC_CAP_DR1,
00394     .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
00395 };