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