/* * Cinepak Video Decoder * Copyright (C) 2003 the ffmpeg project * * This library 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 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * */ /** * @file cinepak.c * Cinepak video decoder * by Ewald Snel <ewald@rambo.its.tudelft.nl> * For more information on the Cinepak algorithm, visit: * http://www.csse.monash.edu.au/~timf/ */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include "common.h" #include "avcodec.h" #include "dsputil.h" typedef struct { uint8_t y0, y1, y2, y3; uint8_t u, v; } cvid_codebook_t; #define MAX_STRIPS 32 typedef struct { uint16_t id; uint16_t x1, y1; uint16_t x2, y2; cvid_codebook_t v4_codebook[256]; cvid_codebook_t v1_codebook[256]; } cvid_strip_t; typedef struct CinepakContext { AVCodecContext *avctx; DSPContext dsp; AVFrame frame; unsigned char *data; int size; int width, height; int palette_video; cvid_strip_t strips[MAX_STRIPS]; } CinepakContext; static void cinepak_decode_codebook (cvid_codebook_t *codebook, int chunk_id, int size, uint8_t *data) { 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 & 0x0400) ? 4 : 6; flag = 0; mask = 0; for (i=0; i < 256; i++) { if ((chunk_id & 0x0100) && !(mask >>= 1)) { if ((data + 4) > eod) break; flag = BE_32 (data); data += 4; mask = 0x80000000; } if (!(chunk_id & 0x0100) || (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_t *strip, int chunk_id, int size, uint8_t *data) { uint8_t *eod = (data + size); uint32_t flag, mask; cvid_codebook_t *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 & 0x0100) && !(mask >>= 1)) { if ((data + 4) > eod) return -1; flag = BE_32 (data); data += 4; mask = 0x80000000; } if (!(chunk_id & 0x0100) || (flag & mask)) { if (!(chunk_id & 0x0200) && !(mask >>= 1)) { if ((data + 4) > eod) return -1; flag = BE_32 (data); data += 4; mask = 0x80000000; } if ((chunk_id & 0x0200) || (~flag & mask)) { if (data >= eod) return -1; 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 -1; 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_t *strip, uint8_t *data, int size) { uint8_t *eod = (data + size); int chunk_id, chunk_size; /* coordinate sanity checks */ if (strip->x1 >= s->width || strip->x2 > s->width || strip->y1 >= s->height || strip->y2 > s->height || strip->x1 >= strip->x2 || strip->y1 >= strip->y2) return -1; while ((data + 4) <= eod) { chunk_id = BE_16 (&data[0]); chunk_size = BE_16 (&data[2]) - 4; if(chunk_size < 0) return -1; data += 4; chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size; switch (chunk_id) { case 0x2000: case 0x2100: case 0x2400: case 0x2500: cinepak_decode_codebook (strip->v4_codebook, chunk_id, chunk_size, data); break; case 0x2200: case 0x2300: case 0x2600: case 0x2700: cinepak_decode_codebook (strip->v1_codebook, chunk_id, chunk_size, data); break; case 0x3000: case 0x3100: case 0x3200: return cinepak_decode_vectors (s, strip, chunk_id, chunk_size, data); } data += chunk_size; } return -1; } static int cinepak_decode (CinepakContext *s) { uint8_t *eod = (s->data + s->size); int i, result, strip_size, frame_flags, num_strips; int y0 = 0; int encoded_buf_size; /* if true, Cinepak data is from a Sega FILM/CPK file */ int sega_film_data = 0; if (s->size < 10) return -1; frame_flags = s->data[0]; num_strips = BE_16 (&s->data[8]); encoded_buf_size = ((s->data[1] << 16) | BE_16 (&s->data[2])); if (encoded_buf_size != s->size) sega_film_data = 1; if (sega_film_data) s->data += 12; else s->data += 10; if (num_strips > MAX_STRIPS) num_strips = MAX_STRIPS; for (i=0; i < num_strips; i++) { if ((s->data + 12) > eod) return -1; s->strips[i].id = BE_16 (s->data); s->strips[i].y1 = y0; s->strips[i].x1 = 0; s->strips[i].y2 = y0 + BE_16 (&s->data[8]); s->strips[i].x2 = s->avctx->width; strip_size = BE_16 (&s->data[2]) - 12; 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 int cinepak_decode_init(AVCodecContext *avctx) { CinepakContext *s = (CinepakContext *)avctx->priv_data; s->avctx = avctx; s->width = (avctx->width + 3) & ~3; s->height = (avctx->height + 3) & ~3; // check for paletted data if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) { s->palette_video = 0; avctx->pix_fmt = PIX_FMT_YUV420P; } else { s->palette_video = 1; avctx->pix_fmt = PIX_FMT_PAL8; } avctx->has_b_frames = 0; dsputil_init(&s->dsp, avctx); s->frame.data[0] = NULL; return 0; } static int cinepak_decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size) { CinepakContext *s = (CinepakContext *)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 (avctx->reget_buffer(avctx, &s->frame)) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return -1; } cinepak_decode(s); if (s->palette_video) { memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE); if (avctx->palctrl->palette_changed) { s->frame.palette_has_changed = 1; avctx->palctrl->palette_changed = 0; } else s->frame.palette_has_changed = 0; } *data_size = sizeof(AVFrame); *(AVFrame*)data = s->frame; /* report that the buffer was completely consumed */ return buf_size; } static int cinepak_decode_end(AVCodecContext *avctx) { CinepakContext *s = (CinepakContext *)avctx->priv_data; if (s->frame.data[0]) avctx->release_buffer(avctx, &s->frame); return 0; } AVCodec cinepak_decoder = { "cinepak", CODEC_TYPE_VIDEO, CODEC_ID_CINEPAK, sizeof(CinepakContext), cinepak_decode_init, NULL, cinepak_decode_end, cinepak_decode_frame, CODEC_CAP_DR1, };