/* * Westwood Studios VQA 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 * VQA Video Decoder * @author Mike Melanson (melanson@pcisys.net) * @see http://wiki.multimedia.cx/index.php?title=VQA * * The VQA video decoder outputs PAL8 or RGB555 colorspace data, depending * on the type of data in the file. * * This decoder needs the 42-byte VQHD header from the beginning * of the VQA file passed through the extradata field. The VQHD header * is laid out as: * * bytes 0-3 chunk fourcc: 'VQHD' * bytes 4-7 chunk size in big-endian format, should be 0x0000002A * bytes 8-49 VQHD chunk data * * Bytes 8-49 are what this decoder expects to see. * * Briefly, VQA is a vector quantized animation format that operates in a * VGA palettized colorspace. It operates on pixel vectors (blocks) * of either 4x2 or 4x4 in size. Compressed VQA chunks can contain vector * codebooks, palette information, and code maps for rendering vectors onto * frames. Any of these components can also be compressed with a run-length * encoding (RLE) algorithm commonly referred to as "format80". * * VQA takes a novel approach to rate control. Each group of n frames * (usually, n = 8) relies on a different vector codebook. Rather than * transporting an entire codebook every 8th frame, the new codebook is * broken up into 8 pieces and sent along with the compressed video chunks * for each of the 8 frames preceding the 8 frames which require the * codebook. A full codebook is also sent on the very first frame of a * file. This is an interesting technique, although it makes random file * seeking difficult despite the fact that the frames are all intracoded. * * V1,2 VQA uses 12-bit codebook indexes. If the 12-bit indexes were * packed into bytes and then RLE compressed, bytewise, the results would * be poor. That is why the coding method divides each index into 2 parts, * the top 4 bits and the bottom 8 bits, then RL encodes the 4-bit pieces * together and the 8-bit pieces together. If most of the vectors are * clustered into one group of 256 vectors, most of the 4-bit index pieces * should be the same. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "libavutil/intreadwrite.h" #include "libavutil/imgutils.h" #include "avcodec.h" #include "bytestream.h" #define PALETTE_COUNT 256 #define VQA_HEADER_SIZE 0x2A /* allocate the maximum vector space, regardless of the file version: * (0xFF00 codebook vectors + 0x100 solid pixel vectors) * (4x4 pixels/block) */ #define MAX_CODEBOOK_VECTORS 0xFF00 #define SOLID_PIXEL_VECTORS 0x100 #define MAX_VECTORS (MAX_CODEBOOK_VECTORS + SOLID_PIXEL_VECTORS) #define MAX_CODEBOOK_SIZE (MAX_VECTORS * 4 * 4) #define CBF0_TAG MKBETAG('C', 'B', 'F', '0') #define CBFZ_TAG MKBETAG('C', 'B', 'F', 'Z') #define CBP0_TAG MKBETAG('C', 'B', 'P', '0') #define CBPZ_TAG MKBETAG('C', 'B', 'P', 'Z') #define CPL0_TAG MKBETAG('C', 'P', 'L', '0') #define CPLZ_TAG MKBETAG('C', 'P', 'L', 'Z') #define VPTZ_TAG MKBETAG('V', 'P', 'T', 'Z') typedef struct VqaContext { AVCodecContext *avctx; AVFrame frame; GetByteContext gb; uint32_t palette[PALETTE_COUNT]; int width; /* width of a frame */ int height; /* height of a frame */ int vector_width; /* width of individual vector */ int vector_height; /* height of individual vector */ int vqa_version; /* this should be either 1, 2 or 3 */ unsigned char *codebook; /* the current codebook */ int codebook_size; unsigned char *next_codebook_buffer; /* accumulator for next codebook */ int next_codebook_buffer_index; unsigned char *decode_buffer; int decode_buffer_size; /* number of frames to go before replacing codebook */ int partial_countdown; int partial_count; } VqaContext; static av_cold int vqa_decode_init(AVCodecContext *avctx) { VqaContext *s = avctx->priv_data; int i, j, codebook_index; s->avctx = avctx; avctx->pix_fmt = PIX_FMT_PAL8; /* make sure the extradata made it */ if (s->avctx->extradata_size != VQA_HEADER_SIZE) { av_log(s->avctx, AV_LOG_ERROR, " VQA video: expected extradata size of %d\n", VQA_HEADER_SIZE); return -1; } /* load up the VQA parameters from the header */ s->vqa_version = s->avctx->extradata[0]; s->width = AV_RL16(&s->avctx->extradata[6]); s->height = AV_RL16(&s->avctx->extradata[8]); if(av_image_check_size(s->width, s->height, 0, avctx)){ s->width= s->height= 0; return -1; } s->vector_width = s->avctx->extradata[10]; s->vector_height = s->avctx->extradata[11]; s->partial_count = s->partial_countdown = s->avctx->extradata[13]; /* the vector dimensions have to meet very stringent requirements */ if ((s->vector_width != 4) || ((s->vector_height != 2) && (s->vector_height != 4))) { /* return without further initialization */ return -1; } if (s->width & (s->vector_width - 1) || s->height & (s->vector_height - 1)) { av_log(avctx, AV_LOG_ERROR, "Image size not multiple of block size\n"); return AVERROR_INVALIDDATA; } /* allocate codebooks */ s->codebook_size = MAX_CODEBOOK_SIZE; s->codebook = av_malloc(s->codebook_size); if (!s->codebook) goto fail; s->next_codebook_buffer = av_malloc(s->codebook_size); if (!s->next_codebook_buffer) goto fail; /* allocate decode buffer */ s->decode_buffer_size = (s->width / s->vector_width) * (s->height / s->vector_height) * 2; s->decode_buffer = av_malloc(s->decode_buffer_size); if (!s->decode_buffer) goto fail; /* initialize the solid-color vectors */ if (s->vector_height == 4) { codebook_index = 0xFF00 * 16; for (i = 0; i < 256; i++) for (j = 0; j < 16; j++) s->codebook[codebook_index++] = i; } else { codebook_index = 0xF00 * 8; for (i = 0; i < 256; i++) for (j = 0; j < 8; j++) s->codebook[codebook_index++] = i; } s->next_codebook_buffer_index = 0; s->frame.data[0] = NULL; return 0; fail: av_freep(&s->codebook); av_freep(&s->next_codebook_buffer); av_freep(&s->decode_buffer); return AVERROR(ENOMEM); } #define CHECK_COUNT() \ if (dest_index + count > dest_size) { \ av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: next op would overflow dest_index\n"); \ av_log(NULL, AV_LOG_ERROR, " VQA video: current dest_index = %d, count = %d, dest_size = %d\n", \ dest_index, count, dest_size); \ return AVERROR_INVALIDDATA; \ } #define CHECK_COPY(idx) \ if (idx < 0 || idx + count > dest_size) { \ av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: next op would overflow dest_index\n"); \ av_log(NULL, AV_LOG_ERROR, " VQA video: current src_pos = %d, count = %d, dest_size = %d\n", \ src_pos, count, dest_size); \ return AVERROR_INVALIDDATA; \ } static int decode_format80(GetByteContext *gb, int src_size, unsigned char *dest, int dest_size, int check_size) { int dest_index = 0; int count, opcode, start; int src_pos; unsigned char color; int i; start = bytestream2_tell(gb); while (bytestream2_tell(gb) - start < src_size) { opcode = bytestream2_get_byte(gb); av_dlog(NULL, " opcode %02X: ", opcode); /* 0x80 means that frame is finished */ if (opcode == 0x80) return 0; if (dest_index >= dest_size) { av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n", dest_index, dest_size); return AVERROR_INVALIDDATA; } if (opcode == 0xFF) { count = bytestream2_get_le16(gb); src_pos = bytestream2_get_le16(gb); av_dlog(NULL, "(1) copy %X bytes from absolute pos %X\n", count, src_pos); CHECK_COUNT(); CHECK_COPY(src_pos); for (i = 0; i < count; i++) dest[dest_index + i] = dest[src_pos + i]; dest_index += count; } else if (opcode == 0xFE) { count = bytestream2_get_le16(gb); color = bytestream2_get_byte(gb); av_dlog(NULL, "(2) set %X bytes to %02X\n", count, color); CHECK_COUNT(); memset(&dest[dest_index], color, count); dest_index += count; } else if ((opcode & 0xC0) == 0xC0) { count = (opcode & 0x3F) + 3; src_pos = bytestream2_get_le16(gb); av_dlog(NULL, "(3) copy %X bytes from absolute pos %X\n", count, src_pos); CHECK_COUNT(); CHECK_COPY(src_pos); for (i = 0; i < count; i++) dest[dest_index + i] = dest[src_pos + i]; dest_index += count; } else if (opcode > 0x80) { count = opcode & 0x3F; av_dlog(NULL, "(4) copy %X bytes from source to dest\n", count); CHECK_COUNT(); bytestream2_get_buffer(gb, &dest[dest_index], count); dest_index += count; } else { count = ((opcode & 0x70) >> 4) + 3; src_pos = bytestream2_get_byte(gb) | ((opcode & 0x0F) << 8); av_dlog(NULL, "(5) copy %X bytes from relpos %X\n", count, src_pos); CHECK_COUNT(); CHECK_COPY(dest_index - src_pos); for (i = 0; i < count; i++) dest[dest_index + i] = dest[dest_index - src_pos + i]; dest_index += count; } } /* validate that the entire destination buffer was filled; this is * important for decoding frame maps since each vector needs to have a * codebook entry; it is not important for compressed codebooks because * not every entry needs to be filled */ if (check_size) if (dest_index < dest_size) av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n", dest_index, dest_size); return 0; // let's display what we decoded anyway } static int vqa_decode_chunk(VqaContext *s) { unsigned int chunk_type; unsigned int chunk_size; int byte_skip; unsigned int index = 0; int i; unsigned char r, g, b; int index_shift; int res; int cbf0_chunk = -1; int cbfz_chunk = -1; int cbp0_chunk = -1; int cbpz_chunk = -1; int cpl0_chunk = -1; int cplz_chunk = -1; int vptz_chunk = -1; int x, y; int lines = 0; int pixel_ptr; int vector_index = 0; int lobyte = 0; int hibyte = 0; int lobytes = 0; int hibytes = s->decode_buffer_size / 2; /* first, traverse through the frame and find the subchunks */ while (bytestream2_get_bytes_left(&s->gb) >= 8) { chunk_type = bytestream2_get_be32u(&s->gb); index = bytestream2_tell(&s->gb); chunk_size = bytestream2_get_be32u(&s->gb); switch (chunk_type) { case CBF0_TAG: cbf0_chunk = index; break; case CBFZ_TAG: cbfz_chunk = index; break; case CBP0_TAG: cbp0_chunk = index; break; case CBPZ_TAG: cbpz_chunk = index; break; case CPL0_TAG: cpl0_chunk = index; break; case CPLZ_TAG: cplz_chunk = index; break; case VPTZ_TAG: vptz_chunk = index; break; default: av_log(s->avctx, AV_LOG_ERROR, " VQA video: Found unknown chunk type: %c%c%c%c (%08X)\n", (chunk_type >> 24) & 0xFF, (chunk_type >> 16) & 0xFF, (chunk_type >> 8) & 0xFF, (chunk_type >> 0) & 0xFF, chunk_type); break; } byte_skip = chunk_size & 0x01; bytestream2_skip(&s->gb, chunk_size + byte_skip); } /* next, deal with the palette */ if ((cpl0_chunk != -1) && (cplz_chunk != -1)) { /* a chunk should not have both chunk types */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CPL0 and CPLZ chunks\n"); return AVERROR_INVALIDDATA; } /* decompress the palette chunk */ if (cplz_chunk != -1) { /* yet to be handled */ } /* convert the RGB palette into the machine's endian format */ if (cpl0_chunk != -1) { bytestream2_seek(&s->gb, cpl0_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* sanity check the palette size */ if (chunk_size / 3 > 256 || chunk_size > bytestream2_get_bytes_left(&s->gb)) { av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found a palette chunk with %d colors\n", chunk_size / 3); return AVERROR_INVALIDDATA; } for (i = 0; i < chunk_size / 3; i++) { /* scale by 4 to transform 6-bit palette -> 8-bit */ r = bytestream2_get_byteu(&s->gb) * 4; g = bytestream2_get_byteu(&s->gb) * 4; b = bytestream2_get_byteu(&s->gb) * 4; s->palette[i] = (r << 16) | (g << 8) | (b); } } /* next, look for a full codebook */ if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) { /* a chunk should not have both chunk types */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBF0 and CBFZ chunks\n"); return AVERROR_INVALIDDATA; } /* decompress the full codebook chunk */ if (cbfz_chunk != -1) { bytestream2_seek(&s->gb, cbfz_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); if ((res = decode_format80(&s->gb, chunk_size, s->codebook, s->codebook_size, 0)) < 0) return res; } /* copy a full codebook */ if (cbf0_chunk != -1) { bytestream2_seek(&s->gb, cbf0_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* sanity check the full codebook size */ if (chunk_size > MAX_CODEBOOK_SIZE) { av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: CBF0 chunk too large (0x%X bytes)\n", chunk_size); return AVERROR_INVALIDDATA; } bytestream2_get_buffer(&s->gb, s->codebook, chunk_size); } /* decode the frame */ if (vptz_chunk == -1) { /* something is wrong if there is no VPTZ chunk */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: no VPTZ chunk found\n"); return AVERROR_INVALIDDATA; } bytestream2_seek(&s->gb, vptz_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); if ((res = decode_format80(&s->gb, chunk_size, s->decode_buffer, s->decode_buffer_size, 1)) < 0) return res; /* render the final PAL8 frame */ if (s->vector_height == 4) index_shift = 4; else index_shift = 3; for (y = 0; y < s->height; y += s->vector_height) { for (x = 0; x < s->width; x += 4, lobytes++, hibytes++) { pixel_ptr = y * s->frame.linesize[0] + x; /* get the vector index, the method for which varies according to * VQA file version */ switch (s->vqa_version) { case 1: lobyte = s->decode_buffer[lobytes * 2]; hibyte = s->decode_buffer[(lobytes * 2) + 1]; vector_index = ((hibyte << 8) | lobyte) >> 3; vector_index <<= index_shift; lines = s->vector_height; /* uniform color fill - a quick hack */ if (hibyte == 0xFF) { while (lines--) { s->frame.data[0][pixel_ptr + 0] = 255 - lobyte; s->frame.data[0][pixel_ptr + 1] = 255 - lobyte; s->frame.data[0][pixel_ptr + 2] = 255 - lobyte; s->frame.data[0][pixel_ptr + 3] = 255 - lobyte; pixel_ptr += s->frame.linesize[0]; } lines=0; } break; case 2: lobyte = s->decode_buffer[lobytes]; hibyte = s->decode_buffer[hibytes]; vector_index = (hibyte << 8) | lobyte; vector_index <<= index_shift; lines = s->vector_height; break; case 3: /* not implemented yet */ lines = 0; break; } while (lines--) { s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++]; s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++]; s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++]; s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++]; pixel_ptr += s->frame.linesize[0]; } } } /* handle partial codebook */ if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) { /* a chunk should not have both chunk types */ av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBP0 and CBPZ chunks\n"); return AVERROR_INVALIDDATA; } if (cbp0_chunk != -1) { bytestream2_seek(&s->gb, cbp0_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* accumulate partial codebook */ bytestream2_get_buffer(&s->gb, &s->next_codebook_buffer[s->next_codebook_buffer_index], chunk_size); s->next_codebook_buffer_index += chunk_size; s->partial_countdown--; if (s->partial_countdown == 0) { /* time to replace codebook */ memcpy(s->codebook, s->next_codebook_buffer, s->next_codebook_buffer_index); /* reset accounting */ s->next_codebook_buffer_index = 0; s->partial_countdown = s->partial_count; } } if (cbpz_chunk != -1) { bytestream2_seek(&s->gb, cbpz_chunk, SEEK_SET); chunk_size = bytestream2_get_be32(&s->gb); /* accumulate partial codebook */ bytestream2_get_buffer(&s->gb, &s->next_codebook_buffer[s->next_codebook_buffer_index], chunk_size); s->next_codebook_buffer_index += chunk_size; s->partial_countdown--; if (s->partial_countdown == 0) { GetByteContext gb; bytestream2_init(&gb, s->next_codebook_buffer, s->next_codebook_buffer_index); /* decompress codebook */ if ((res = decode_format80(&gb, s->next_codebook_buffer_index, s->codebook, s->codebook_size, 0)) < 0) return res; /* reset accounting */ s->next_codebook_buffer_index = 0; s->partial_countdown = s->partial_count; } } return 0; } static int vqa_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { VqaContext *s = avctx->priv_data; int res; if (s->frame.data[0]) avctx->release_buffer(avctx, &s->frame); if (avctx->get_buffer(avctx, &s->frame)) { av_log(s->avctx, AV_LOG_ERROR, " VQA Video: get_buffer() failed\n"); return -1; } bytestream2_init(&s->gb, avpkt->data, avpkt->size); if ((res = vqa_decode_chunk(s)) < 0) return res; /* make the palette available on the way out */ memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4); s->frame.palette_has_changed = 1; *data_size = sizeof(AVFrame); *(AVFrame*)data = s->frame; /* report that the buffer was completely consumed */ return avpkt->size; } static av_cold int vqa_decode_end(AVCodecContext *avctx) { VqaContext *s = avctx->priv_data; av_freep(&s->codebook); av_freep(&s->next_codebook_buffer); av_freep(&s->decode_buffer); if (s->frame.data[0]) avctx->release_buffer(avctx, &s->frame); return 0; } AVCodec ff_vqa_decoder = { .name = "vqavideo", .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_WS_VQA, .priv_data_size = sizeof(VqaContext), .init = vqa_decode_init, .close = vqa_decode_end, .decode = vqa_decode_frame, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("Westwood Studios VQA (Vector Quantized Animation) video"), };