/* * Sierra VMD video decoder * * 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 * Sierra VMD video decoder * by Vladimir "VAG" Gneushev (vagsoft at mail.ru) * for more information on the Sierra VMD format, visit: * http://www.pcisys.net/~melanson/codecs/ * * The video decoder outputs PAL8 colorspace data. The decoder expects * a 0x330-byte VMD file header to be transmitted via extradata during * codec initialization. Each encoded frame that is sent to this decoder * is expected to be prepended with the appropriate 16-byte frame * information record from the VMD file. */ #include <string.h> #include "libavutil/common.h" #include "libavutil/intreadwrite.h" #include "avcodec.h" #include "internal.h" #include "bytestream.h" #define VMD_HEADER_SIZE 0x330 #define PALETTE_COUNT 256 typedef struct VmdVideoContext { AVCodecContext *avctx; AVFrame *prev_frame; const unsigned char *buf; int size; unsigned char palette[PALETTE_COUNT * 4]; unsigned char *unpack_buffer; int unpack_buffer_size; int x_off, y_off; } VmdVideoContext; #define QUEUE_SIZE 0x1000 #define QUEUE_MASK 0x0FFF static void lz_unpack(const unsigned char *src, int src_len, unsigned char *dest, int dest_len) { unsigned char *d; unsigned char *d_end; unsigned char queue[QUEUE_SIZE]; unsigned int qpos; unsigned int dataleft; unsigned int chainofs; unsigned int chainlen; unsigned int speclen; unsigned char tag; unsigned int i, j; GetByteContext gb; bytestream2_init(&gb, src, src_len); d = dest; d_end = d + dest_len; dataleft = bytestream2_get_le32(&gb); memset(queue, 0x20, QUEUE_SIZE); if (bytestream2_get_bytes_left(&gb) < 4) return; if (bytestream2_peek_le32(&gb) == 0x56781234) { bytestream2_get_le32(&gb); qpos = 0x111; speclen = 0xF + 3; } else { qpos = 0xFEE; speclen = 100; /* no speclen */ } while (dataleft > 0 && bytestream2_get_bytes_left(&gb) > 0) { tag = bytestream2_get_byteu(&gb); if ((tag == 0xFF) && (dataleft > 8)) { if (d + 8 > d_end || bytestream2_get_bytes_left(&gb) < 8) return; for (i = 0; i < 8; i++) { queue[qpos++] = *d++ = bytestream2_get_byteu(&gb); qpos &= QUEUE_MASK; } dataleft -= 8; } else { for (i = 0; i < 8; i++) { if (dataleft == 0) break; if (tag & 0x01) { if (d + 1 > d_end || bytestream2_get_bytes_left(&gb) < 1) return; queue[qpos++] = *d++ = bytestream2_get_byte(&gb); qpos &= QUEUE_MASK; dataleft--; } else { chainofs = bytestream2_get_byte(&gb); chainofs |= ((bytestream2_peek_byte(&gb) & 0xF0) << 4); chainlen = (bytestream2_get_byte(&gb) & 0x0F) + 3; if (chainlen == speclen) { chainlen = bytestream2_get_byte(&gb) + 0xF + 3; } if (d + chainlen > d_end) return; for (j = 0; j < chainlen; j++) { *d = queue[chainofs++ & QUEUE_MASK]; queue[qpos++] = *d++; qpos &= QUEUE_MASK; } dataleft -= chainlen; } tag >>= 1; } } } } static int rle_unpack(const unsigned char *src, unsigned char *dest, int src_count, int src_size, int dest_len) { unsigned char *pd; int i, l, used = 0; unsigned char *dest_end = dest + dest_len; GetByteContext gb; uint16_t run_val; bytestream2_init(&gb, src, src_size); pd = dest; if (src_count & 1) { if (bytestream2_get_bytes_left(&gb) < 1) return 0; *pd++ = bytestream2_get_byteu(&gb); used++; } do { if (bytestream2_get_bytes_left(&gb) < 1) break; l = bytestream2_get_byteu(&gb); if (l & 0x80) { l = (l & 0x7F) * 2; if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < l) return bytestream2_tell(&gb); bytestream2_get_buffer(&gb, pd, l); pd += l; } else { if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < 2) return bytestream2_tell(&gb); run_val = bytestream2_get_ne16(&gb); for (i = 0; i < l; i++) { AV_WN16(pd, run_val); pd += 2; } l *= 2; } used += l; } while (used < src_count); return bytestream2_tell(&gb); } static int vmd_decode(VmdVideoContext *s, AVFrame *frame) { int i; unsigned int *palette32; unsigned char r, g, b; GetByteContext gb; unsigned char meth; unsigned char *dp; /* pointer to current frame */ unsigned char *pp; /* pointer to previous frame */ unsigned char len; int ofs; int frame_x, frame_y; int frame_width, frame_height; frame_x = AV_RL16(&s->buf[6]); frame_y = AV_RL16(&s->buf[8]); frame_width = AV_RL16(&s->buf[10]) - frame_x + 1; frame_height = AV_RL16(&s->buf[12]) - frame_y + 1; if (frame_x < 0 || frame_width < 0 || frame_x >= s->avctx->width || frame_width > s->avctx->width || frame_x + frame_width > s->avctx->width) { av_log(s->avctx, AV_LOG_ERROR, "Invalid horizontal range %d-%d\n", frame_x, frame_width); return AVERROR_INVALIDDATA; } if (frame_y < 0 || frame_height < 0 || frame_y >= s->avctx->height || frame_height > s->avctx->height || frame_y + frame_height > s->avctx->height) { av_log(s->avctx, AV_LOG_ERROR, "Invalid vertical range %d-%d\n", frame_x, frame_width); return AVERROR_INVALIDDATA; } if ((frame_width == s->avctx->width && frame_height == s->avctx->height) && (frame_x || frame_y)) { s->x_off = frame_x; s->y_off = frame_y; } frame_x -= s->x_off; frame_y -= s->y_off; /* if only a certain region will be updated, copy the entire previous * frame before the decode */ if (s->prev_frame->data[0] && (frame_x || frame_y || (frame_width != s->avctx->width) || (frame_height != s->avctx->height))) { memcpy(frame->data[0], s->prev_frame->data[0], s->avctx->height * frame->linesize[0]); } /* check if there is a new palette */ bytestream2_init(&gb, s->buf + 16, s->size - 16); if (s->buf[15] & 0x02) { bytestream2_skip(&gb, 2); palette32 = (unsigned int *)s->palette; if (bytestream2_get_bytes_left(&gb) >= PALETTE_COUNT * 3) { for (i = 0; i < PALETTE_COUNT; i++) { r = bytestream2_get_byteu(&gb) * 4; g = bytestream2_get_byteu(&gb) * 4; b = bytestream2_get_byteu(&gb) * 4; palette32[i] = (r << 16) | (g << 8) | (b); } } else { av_log(s->avctx, AV_LOG_ERROR, "Incomplete palette\n"); return AVERROR_INVALIDDATA; } s->size -= PALETTE_COUNT * 3 + 2; } if (!s->size) return 0; /* originally UnpackFrame in VAG's code */ if (bytestream2_get_bytes_left(&gb) < 1) return AVERROR_INVALIDDATA; meth = bytestream2_get_byteu(&gb); if (meth & 0x80) { if (!s->unpack_buffer_size) { av_log(s->avctx, AV_LOG_ERROR, "Trying to unpack LZ-compressed frame with no LZ buffer\n"); return AVERROR_INVALIDDATA; } lz_unpack(gb.buffer, bytestream2_get_bytes_left(&gb), s->unpack_buffer, s->unpack_buffer_size); meth &= 0x7F; bytestream2_init(&gb, s->unpack_buffer, s->unpack_buffer_size); } dp = &frame->data[0][frame_y * frame->linesize[0] + frame_x]; pp = &s->prev_frame->data[0][frame_y * s->prev_frame->linesize[0] + frame_x]; switch (meth) { case 1: for (i = 0; i < frame_height; i++) { ofs = 0; do { len = bytestream2_get_byte(&gb); if (len & 0x80) { len = (len & 0x7F) + 1; if (ofs + len > frame_width || bytestream2_get_bytes_left(&gb) < len) return AVERROR_INVALIDDATA; bytestream2_get_buffer(&gb, &dp[ofs], len); ofs += len; } else { /* interframe pixel copy */ if (ofs + len + 1 > frame_width || !s->prev_frame->data[0]) return AVERROR_INVALIDDATA; memcpy(&dp[ofs], &pp[ofs], len + 1); ofs += len + 1; } } while (ofs < frame_width); if (ofs > frame_width) { av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n", ofs, frame_width); return AVERROR_INVALIDDATA; } dp += frame->linesize[0]; pp += s->prev_frame->linesize[0]; } break; case 2: for (i = 0; i < frame_height; i++) { bytestream2_get_buffer(&gb, dp, frame_width); dp += frame->linesize[0]; pp += s->prev_frame->linesize[0]; } break; case 3: for (i = 0; i < frame_height; i++) { ofs = 0; do { len = bytestream2_get_byte(&gb); if (len & 0x80) { len = (len & 0x7F) + 1; if (bytestream2_peek_byte(&gb) == 0xFF) { int slen = len; bytestream2_get_byte(&gb); len = rle_unpack(gb.buffer, &dp[ofs], len, bytestream2_get_bytes_left(&gb), frame_width - ofs); ofs += slen; bytestream2_skip(&gb, len); } else { bytestream2_get_buffer(&gb, &dp[ofs], len); ofs += len; } } else { /* interframe pixel copy */ if (ofs + len + 1 > frame_width || !s->prev_frame->data[0]) return AVERROR_INVALIDDATA; memcpy(&dp[ofs], &pp[ofs], len + 1); ofs += len + 1; } } while (ofs < frame_width); if (ofs > frame_width) { av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n", ofs, frame_width); return AVERROR_INVALIDDATA; } dp += frame->linesize[0]; pp += s->prev_frame->linesize[0]; } break; } return 0; } static av_cold int vmdvideo_decode_end(AVCodecContext *avctx) { VmdVideoContext *s = avctx->priv_data; av_frame_free(&s->prev_frame); av_free(s->unpack_buffer); return 0; } static av_cold int vmdvideo_decode_init(AVCodecContext *avctx) { VmdVideoContext *s = avctx->priv_data; int i; unsigned int *palette32; int palette_index = 0; unsigned char r, g, b; unsigned char *vmd_header; unsigned char *raw_palette; s->avctx = avctx; avctx->pix_fmt = AV_PIX_FMT_PAL8; /* make sure the VMD header made it */ if (s->avctx->extradata_size != VMD_HEADER_SIZE) { av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n", VMD_HEADER_SIZE); return -1; } vmd_header = (unsigned char *)avctx->extradata; s->unpack_buffer_size = AV_RL32(&vmd_header[800]); if (s->unpack_buffer_size) { s->unpack_buffer = av_malloc(s->unpack_buffer_size); if (!s->unpack_buffer) return AVERROR(ENOMEM); } /* load up the initial palette */ raw_palette = &vmd_header[28]; palette32 = (unsigned int *)s->palette; for (i = 0; i < PALETTE_COUNT; i++) { r = raw_palette[palette_index++] * 4; g = raw_palette[palette_index++] * 4; b = raw_palette[palette_index++] * 4; palette32[i] = (r << 16) | (g << 8) | (b); } s->prev_frame = av_frame_alloc(); if (!s->prev_frame) { vmdvideo_decode_end(avctx); return AVERROR(ENOMEM); } return 0; } static int vmdvideo_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; VmdVideoContext *s = avctx->priv_data; AVFrame *frame = data; int ret; s->buf = buf; s->size = buf_size; if (buf_size < 16) return AVERROR_INVALIDDATA; if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) { av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n"); return ret; } if ((ret = vmd_decode(s, frame)) < 0) return ret; /* make the palette available on the way out */ memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4); /* shuffle frames */ av_frame_unref(s->prev_frame); if ((ret = av_frame_ref(s->prev_frame, frame)) < 0) return ret; *got_frame = 1; /* report that the buffer was completely consumed */ return buf_size; } AVCodec ff_vmdvideo_decoder = { .name = "vmdvideo", .long_name = NULL_IF_CONFIG_SMALL("Sierra VMD video"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_VMDVIDEO, .priv_data_size = sizeof(VmdVideoContext), .init = vmdvideo_decode_init, .close = vmdvideo_decode_end, .decode = vmdvideo_decode_frame, .capabilities = AV_CODEC_CAP_DR1, };