/* * Cinepak Video Decoder * Copyright (C) 2003 the ffmpeg project * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Cinepak video decoder * @author Ewald Snel <ewald@rambo.its.tudelft.nl> * * @see For more information on the Cinepak algorithm, visit: * http://www.csse.monash.edu.au/~timf/ * @see For more information on the quirky data inside Sega FILM/CPK files, visit: * http://wiki.multimedia.cx/index.php?title=Sega_FILM */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "libavutil/common.h" #include "libavutil/intreadwrite.h" #include "avcodec.h" typedef struct { uint8_t y0, y1, y2, y3; uint8_t u, v; } cvid_codebook; #define MAX_STRIPS 32 typedef struct { uint16_t id; uint16_t x1, y1; uint16_t x2, y2; cvid_codebook v4_codebook[256]; cvid_codebook v1_codebook[256]; } cvid_strip; typedef struct CinepakContext { AVCodecContext *avctx; AVFrame frame; const unsigned char *data; int size; int width, height; int palette_video; cvid_strip strips[MAX_STRIPS]; int sega_film_skip_bytes; uint32_t pal[256]; } CinepakContext; static void cinepak_decode_codebook (cvid_codebook *codebook, int chunk_id, int size, const uint8_t *data) { const uint8_t *eod = (data + size); uint32_t flag, mask; int i, n; /* check if this chunk contains 4- or 6-element vectors */ n = (chunk_id & 0x04) ? 4 : 6; flag = 0; mask = 0; for (i=0; i < 256; i++) { if ((chunk_id & 0x01) && !(mask >>= 1)) { if ((data + 4) > eod) break; flag = AV_RB32 (data); data += 4; mask = 0x80000000; } if (!(chunk_id & 0x01) || (flag & mask)) { if ((data + n) > eod) break; if (n == 6) { codebook[i].y0 = *data++; codebook[i].y1 = *data++; codebook[i].y2 = *data++; codebook[i].y3 = *data++; codebook[i].u = 128 + *data++; codebook[i].v = 128 + *data++; } else { /* this codebook type indicates either greyscale or * palettized video; if palettized, U & V components will * not be used so it is safe to set them to 128 for the * benefit of greyscale rendering in YUV420P */ codebook[i].y0 = *data++; codebook[i].y1 = *data++; codebook[i].y2 = *data++; codebook[i].y3 = *data++; codebook[i].u = 128; codebook[i].v = 128; } } } } static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip, int chunk_id, int size, const uint8_t *data) { const uint8_t *eod = (data + size); uint32_t flag, mask; cvid_codebook *codebook; unsigned int x, y; uint32_t iy[4]; uint32_t iu[2]; uint32_t iv[2]; flag = 0; mask = 0; for (y=strip->y1; y < strip->y2; y+=4) { iy[0] = strip->x1 + (y * s->frame.linesize[0]); iy[1] = iy[0] + s->frame.linesize[0]; iy[2] = iy[1] + s->frame.linesize[0]; iy[3] = iy[2] + s->frame.linesize[0]; iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]); iu[1] = iu[0] + s->frame.linesize[1]; iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]); iv[1] = iv[0] + s->frame.linesize[2]; for (x=strip->x1; x < strip->x2; x+=4) { if ((chunk_id & 0x01) && !(mask >>= 1)) { if ((data + 4) > eod) return AVERROR_INVALIDDATA; flag = AV_RB32 (data); data += 4; mask = 0x80000000; } if (!(chunk_id & 0x01) || (flag & mask)) { if (!(chunk_id & 0x02) && !(mask >>= 1)) { if ((data + 4) > eod) return AVERROR_INVALIDDATA; flag = AV_RB32 (data); data += 4; mask = 0x80000000; } if ((chunk_id & 0x02) || (~flag & mask)) { if (data >= eod) return AVERROR_INVALIDDATA; codebook = &strip->v1_codebook[*data++]; s->frame.data[0][iy[0] + 0] = codebook->y0; s->frame.data[0][iy[0] + 1] = codebook->y0; s->frame.data[0][iy[1] + 0] = codebook->y0; s->frame.data[0][iy[1] + 1] = codebook->y0; if (!s->palette_video) { s->frame.data[1][iu[0]] = codebook->u; s->frame.data[2][iv[0]] = codebook->v; } s->frame.data[0][iy[0] + 2] = codebook->y1; s->frame.data[0][iy[0] + 3] = codebook->y1; s->frame.data[0][iy[1] + 2] = codebook->y1; s->frame.data[0][iy[1] + 3] = codebook->y1; if (!s->palette_video) { s->frame.data[1][iu[0] + 1] = codebook->u; s->frame.data[2][iv[0] + 1] = codebook->v; } s->frame.data[0][iy[2] + 0] = codebook->y2; s->frame.data[0][iy[2] + 1] = codebook->y2; s->frame.data[0][iy[3] + 0] = codebook->y2; s->frame.data[0][iy[3] + 1] = codebook->y2; if (!s->palette_video) { s->frame.data[1][iu[1]] = codebook->u; s->frame.data[2][iv[1]] = codebook->v; } s->frame.data[0][iy[2] + 2] = codebook->y3; s->frame.data[0][iy[2] + 3] = codebook->y3; s->frame.data[0][iy[3] + 2] = codebook->y3; s->frame.data[0][iy[3] + 3] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[1] + 1] = codebook->u; s->frame.data[2][iv[1] + 1] = codebook->v; } } else if (flag & mask) { if ((data + 4) > eod) return AVERROR_INVALIDDATA; codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[0] + 0] = codebook->y0; s->frame.data[0][iy[0] + 1] = codebook->y1; s->frame.data[0][iy[1] + 0] = codebook->y2; s->frame.data[0][iy[1] + 1] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[0]] = codebook->u; s->frame.data[2][iv[0]] = codebook->v; } codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[0] + 2] = codebook->y0; s->frame.data[0][iy[0] + 3] = codebook->y1; s->frame.data[0][iy[1] + 2] = codebook->y2; s->frame.data[0][iy[1] + 3] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[0] + 1] = codebook->u; s->frame.data[2][iv[0] + 1] = codebook->v; } codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[2] + 0] = codebook->y0; s->frame.data[0][iy[2] + 1] = codebook->y1; s->frame.data[0][iy[3] + 0] = codebook->y2; s->frame.data[0][iy[3] + 1] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[1]] = codebook->u; s->frame.data[2][iv[1]] = codebook->v; } codebook = &strip->v4_codebook[*data++]; s->frame.data[0][iy[2] + 2] = codebook->y0; s->frame.data[0][iy[2] + 3] = codebook->y1; s->frame.data[0][iy[3] + 2] = codebook->y2; s->frame.data[0][iy[3] + 3] = codebook->y3; if (!s->palette_video) { s->frame.data[1][iu[1] + 1] = codebook->u; s->frame.data[2][iv[1] + 1] = codebook->v; } } } iy[0] += 4; iy[1] += 4; iy[2] += 4; iy[3] += 4; iu[0] += 2; iu[1] += 2; iv[0] += 2; iv[1] += 2; } } return 0; } static int cinepak_decode_strip (CinepakContext *s, cvid_strip *strip, const uint8_t *data, int size) { const uint8_t *eod = (data + size); int chunk_id, chunk_size; /* coordinate sanity checks */ if (strip->x2 > s->width || strip->y2 > s->height || strip->x1 >= strip->x2 || strip->y1 >= strip->y2) return AVERROR_INVALIDDATA; while ((data + 4) <= eod) { chunk_id = data[0]; chunk_size = AV_RB24 (&data[1]) - 4; if(chunk_size < 0) return AVERROR_INVALIDDATA; data += 4; chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size; switch (chunk_id) { case 0x20: case 0x21: case 0x24: case 0x25: cinepak_decode_codebook (strip->v4_codebook, chunk_id, chunk_size, data); break; case 0x22: case 0x23: case 0x26: case 0x27: cinepak_decode_codebook (strip->v1_codebook, chunk_id, chunk_size, data); break; case 0x30: case 0x31: case 0x32: return cinepak_decode_vectors (s, strip, chunk_id, chunk_size, data); } data += chunk_size; } return AVERROR_INVALIDDATA; } static int cinepak_decode (CinepakContext *s) { const uint8_t *eod = (s->data + s->size); int i, result, strip_size, frame_flags, num_strips; int y0 = 0; int encoded_buf_size; if (s->size < 10) return AVERROR_INVALIDDATA; frame_flags = s->data[0]; num_strips = AV_RB16 (&s->data[8]); encoded_buf_size = AV_RB24(&s->data[1]); /* if this is the first frame, check for deviant Sega FILM data */ if (s->sega_film_skip_bytes == -1) { if (!encoded_buf_size) { av_log_ask_for_sample(s->avctx, "encoded_buf_size is 0"); return AVERROR_PATCHWELCOME; } if (encoded_buf_size != s->size && (s->size % encoded_buf_size) != 0) { /* If the encoded frame size differs from the frame size as indicated * by the container file, this data likely comes from a Sega FILM/CPK file. * If the frame header is followed by the bytes FE 00 00 06 00 00 then * this is probably one of the two known files that have 6 extra bytes * after the frame header. Else, assume 2 extra bytes. The container * size also cannot be a multiple of the encoded size. */ if (s->size >= 16 && (s->data[10] == 0xFE) && (s->data[11] == 0x00) && (s->data[12] == 0x00) && (s->data[13] == 0x06) && (s->data[14] == 0x00) && (s->data[15] == 0x00)) s->sega_film_skip_bytes = 6; else s->sega_film_skip_bytes = 2; } else s->sega_film_skip_bytes = 0; } s->data += 10 + s->sega_film_skip_bytes; num_strips = FFMIN(num_strips, MAX_STRIPS); for (i=0; i < num_strips; i++) { if ((s->data + 12) > eod) return AVERROR_INVALIDDATA; s->strips[i].id = s->data[0]; s->strips[i].y1 = y0; s->strips[i].x1 = 0; s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]); s->strips[i].x2 = s->avctx->width; strip_size = AV_RB24 (&s->data[1]) - 12; if (strip_size < 0) return AVERROR_INVALIDDATA; s->data += 12; strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size; if ((i > 0) && !(frame_flags & 0x01)) { memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook, sizeof(s->strips[i].v4_codebook)); memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook, sizeof(s->strips[i].v1_codebook)); } result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size); if (result != 0) return result; s->data += strip_size; y0 = s->strips[i].y2; } return 0; } static av_cold int cinepak_decode_init(AVCodecContext *avctx) { CinepakContext *s = avctx->priv_data; s->avctx = avctx; s->width = (avctx->width + 3) & ~3; s->height = (avctx->height + 3) & ~3; s->sega_film_skip_bytes = -1; /* uninitialized state */ // check for paletted data if (avctx->bits_per_coded_sample != 8) { s->palette_video = 0; avctx->pix_fmt = AV_PIX_FMT_YUV420P; } else { s->palette_video = 1; avctx->pix_fmt = AV_PIX_FMT_PAL8; } s->frame.data[0] = NULL; return 0; } static int cinepak_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int ret = 0, buf_size = avpkt->size; CinepakContext *s = avctx->priv_data; s->data = buf; s->size = buf_size; s->frame.reference = 1; s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; if ((ret = avctx->reget_buffer(avctx, &s->frame))) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return ret; } if (s->palette_video) { const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); if (pal) { s->frame.palette_has_changed = 1; memcpy(s->pal, pal, AVPALETTE_SIZE); } } cinepak_decode(s); if (s->palette_video) memcpy (s->frame.data[1], s->pal, AVPALETTE_SIZE); *got_frame = 1; *(AVFrame*)data = s->frame; /* report that the buffer was completely consumed */ return buf_size; } static av_cold int cinepak_decode_end(AVCodecContext *avctx) { CinepakContext *s = avctx->priv_data; if (s->frame.data[0]) avctx->release_buffer(avctx, &s->frame); return 0; } AVCodec ff_cinepak_decoder = { .name = "cinepak", .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_CINEPAK, .priv_data_size = sizeof(CinepakContext), .init = cinepak_decode_init, .close = cinepak_decode_end, .decode = cinepak_decode_frame, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("Cinepak"), };