/* * Copyright (C) 2005 Ole Andr� Vadla Ravn�s <oleavr@gmail.com> * Copyright (C) 2008 Ramiro Polla <ramiro@lisha.ufsc.br> * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <stdlib.h> #include <string.h> #include <stdint.h> #include "avcodec.h" #include "get_bits.h" #include "bytestream.h" #include "dsputil.h" #define MIMIC_HEADER_SIZE 20 typedef struct { AVCodecContext *avctx; int num_vblocks[3]; int num_hblocks[3]; void *swap_buf; int swap_buf_size; int cur_index; int prev_index; AVFrame buf_ptrs [16]; AVPicture flipped_ptrs[16]; DECLARE_ALIGNED(16, DCTELEM, dct_block)[64]; GetBitContext gb; ScanTable scantable; DSPContext dsp; VLC vlc; } MimicContext; static const uint32_t huffcodes[] = { 0x0000000a, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x0000000b, 0x0000001b, 0x00000038, 0x00000078, 0x00000079, 0x0000007a, 0x000000f9, 0x000000fa, 0x000003fb, 0x000007f8, 0x000007f9, 0x000007fa, 0x000007fb, 0x00000ff8, 0x00000ff9, 0x00000001, 0x00000039, 0x0000007b, 0x000000fb, 0x000001f8, 0x000001f9, 0x00000ffa, 0x00000ffb, 0x00001ff8, 0x00001ff9, 0x00001ffa, 0x00001ffb, 0x00003ff8, 0x00003ff9, 0x00003ffa, 0x00000000, 0x00000004, 0x0000003a, 0x000001fa, 0x00003ffb, 0x00007ff8, 0x00007ff9, 0x00007ffa, 0x00007ffb, 0x0000fff8, 0x0000fff9, 0x0000fffa, 0x0000fffb, 0x0001fff8, 0x0001fff9, 0x0001fffa, 0x00000000, 0x0000000c, 0x000000f8, 0x000001fb, 0x0001fffb, 0x0003fff8, 0x0003fff9, 0x0003fffa, 0x0003fffb, 0x0007fff8, 0x0007fff9, 0x0007fffa, 0x0007fffb, 0x000ffff8, 0x000ffff9, 0x000ffffa, 0x00000000, 0x0000001a, 0x000003f8, 0x000ffffb, 0x001ffff8, 0x001ffff9, 0x001ffffa, 0x001ffffb, 0x003ffff8, 0x003ffff9, 0x003ffffa, 0x003ffffb, 0x007ffff8, 0x007ffff9, 0x007ffffa, 0x007ffffb, 0x00000000, 0x0000003b, 0x000003f9, 0x00fffff8, 0x00fffff9, 0x00fffffa, 0x00fffffb, 0x01fffff8, 0x01fffff9, 0x01fffffa, 0x01fffffb, 0x03fffff8, 0x03fffff9, 0x03fffffa, 0x03fffffb, 0x07fffff8, 0x00000000, 0x000003fa, 0x07fffff9, 0x07fffffa, 0x07fffffb, 0x0ffffff8, 0x0ffffff9, 0x0ffffffa, 0x0ffffffb, 0x1ffffff8, 0x1ffffff9, 0x1ffffffa, 0x1ffffffb, 0x3ffffff8, 0x3ffffff9, 0x3ffffffa, }; static const uint8_t huffbits[] = { 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 5, 6, 7, 7, 7, 8, 8, 10, 11, 11, 11, 11, 12, 12, 2, 6, 7, 8, 9, 9, 12, 12, 13, 13, 13, 13, 14, 14, 14, 0, 3, 6, 9, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 0, 4, 8, 9, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 0, 5, 10, 20, 21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 0, 6, 10, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 27, 0, 10, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30, }; static const uint8_t col_zag[64] = { 0, 8, 1, 2, 9, 16, 24, 17, 10, 3, 4, 11, 18, 25, 32, 40, 33, 26, 19, 12, 5, 6, 13, 20, 27, 34, 41, 48, 56, 49, 42, 35, 28, 21, 14, 7, 15, 22, 29, 36, 43, 50, 57, 58, 51, 44, 37, 30, 23, 31, 38, 45, 52, 59, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63, }; static av_cold int mimic_decode_init(AVCodecContext *avctx) { MimicContext *ctx = avctx->priv_data; ctx->prev_index = 0; ctx->cur_index = 15; if(init_vlc(&ctx->vlc, 11, FF_ARRAY_ELEMS(huffbits), huffbits, 1, 1, huffcodes, 4, 4, 0)) { av_log(avctx, AV_LOG_ERROR, "error initializing vlc table\n"); return -1; } dsputil_init(&ctx->dsp, avctx); ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, col_zag); return 0; } static const int8_t vlcdec_lookup[9][64] = { { 0, }, { -1, 1, }, { -3, 3, -2, 2, }, { -7, 7, -6, 6, -5, 5, -4, 4, }, { -15, 15, -14, 14, -13, 13, -12, 12, -11, 11, -10, 10, -9, 9, -8, 8, }, { -31, 31, -30, 30, -29, 29, -28, 28, -27, 27, -26, 26, -25, 25, -24, 24, -23, 23, -22, 22, -21, 21, -20, 20, -19, 19, -18, 18, -17, 17, -16, 16, }, { -63, 63, -62, 62, -61, 61, -60, 60, -59, 59, -58, 58, -57, 57, -56, 56, -55, 55, -54, 54, -53, 53, -52, 52, -51, 51, -50, 50, -49, 49, -48, 48, -47, 47, -46, 46, -45, 45, -44, 44, -43, 43, -42, 42, -41, 41, -40, 40, -39, 39, -38, 38, -37, 37, -36, 36, -35, 35, -34, 34, -33, 33, -32, 32, }, { -127, 127, -126, 126, -125, 125, -124, 124, -123, 123, -122, 122, -121, 121, -120, 120, -119, 119, -118, 118, -117, 117, -116, 116, -115, 115, -114, 114, -113, 113, -112, 112, -111, 111, -110, 110, -109, 109, -108, 108, -107, 107, -106, 106, -105, 105, -104, 104, -103, 103, -102, 102, -101, 101, -100, 100, -99, 99, -98, 98, -97, 97, -96, 96, }, { -95, 95, -94, 94, -93, 93, -92, 92, -91, 91, -90, 90, -89, 89, -88, 88, -87, 87, -86, 86, -85, 85, -84, 84, -83, 83, -82, 82, -81, 81, -80, 80, -79, 79, -78, 78, -77, 77, -76, 76, -75, 75, -74, 74, -73, 73, -72, 72, -71, 71, -70, 70, -69, 69, -68, 68, -67, 67, -66, 66, -65, 65, -64, 64, }, }; static int vlc_decode_block(MimicContext *ctx, int num_coeffs, int qscale) { DCTELEM *block = ctx->dct_block; unsigned int pos; ctx->dsp.clear_block(block); block[0] = get_bits(&ctx->gb, 8) << 3; for(pos = 1; pos < num_coeffs; pos++) { uint32_t vlc, num_bits; int value; int coeff; vlc = get_vlc2(&ctx->gb, ctx->vlc.table, ctx->vlc.bits, 3); if(!vlc) /* end-of-block code */ return 1; if(vlc == -1) return 0; /* pos_add and num_bits are coded in the vlc code */ pos += vlc&15; // pos_add num_bits = vlc>>4; // num_bits if(pos >= 64) return 0; value = get_bits(&ctx->gb, num_bits); /* FFmpeg's IDCT behaves somewhat different from the original code, so * a factor of 4 was added to the input */ coeff = vlcdec_lookup[num_bits][value]; if(pos<3) coeff <<= 4; else /* TODO Use >> 10 instead of / 1001 */ coeff = (coeff * qscale) / 1001; block[ctx->scantable.permutated[pos]] = coeff; } return 1; } static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe) { int y, x, plane; for(plane = 0; plane < 3; plane++) { const int is_chroma = !!plane; const int qscale = av_clip(10000-quality,is_chroma?1000:2000,10000)<<2; const int stride = ctx->flipped_ptrs[ctx->cur_index].linesize[plane]; const uint8_t *src = ctx->flipped_ptrs[ctx->prev_index].data[plane]; uint8_t *dst = ctx->flipped_ptrs[ctx->cur_index ].data[plane]; for(y = 0; y < ctx->num_vblocks[plane]; y++) { for(x = 0; x < ctx->num_hblocks[plane]; x++) { /* Check for a change condition in the current block. * - iframes always change. * - Luma plane changes on get_bits1 == 0 * - Chroma planes change on get_bits1 == 1 */ if(is_iframe || get_bits1(&ctx->gb) == is_chroma) { /* Luma planes may use a backreference from the 15 last * frames preceding the previous. (get_bits1 == 1) * Chroma planes don't use backreferences. */ if(is_chroma || is_iframe || !get_bits1(&ctx->gb)) { if(!vlc_decode_block(ctx, num_coeffs, qscale)) return 0; ctx->dsp.idct_put(dst, stride, ctx->dct_block); } else { unsigned int backref = get_bits(&ctx->gb, 4); int index = (ctx->cur_index+backref)&15; uint8_t *p = ctx->flipped_ptrs[index].data[0]; if(p) { p += src - ctx->flipped_ptrs[ctx->prev_index].data[plane]; ctx->dsp.put_pixels_tab[1][0](dst, p, stride, 8); } else { av_log(ctx->avctx, AV_LOG_ERROR, "No such backreference! Buggy sample.\n"); } } } else { ctx->dsp.put_pixels_tab[1][0](dst, src, stride, 8); } src += 8; dst += 8; } src += (stride - ctx->num_hblocks[plane])<<3; dst += (stride - ctx->num_hblocks[plane])<<3; } } return 1; } /** * Flip the buffer upside-down and put it in the YVU order to match the * way Mimic encodes frames. */ static void prepare_avpic(MimicContext *ctx, AVPicture *dst, AVPicture *src) { int i; dst->data[0] = src->data[0]+( ctx->avctx->height -1)*src->linesize[0]; dst->data[1] = src->data[2]+((ctx->avctx->height>>1)-1)*src->linesize[2]; dst->data[2] = src->data[1]+((ctx->avctx->height>>1)-1)*src->linesize[1]; for(i = 0; i < 3; i++) dst->linesize[i] = -src->linesize[i]; } static int mimic_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; MimicContext *ctx = avctx->priv_data; int is_pframe; int width, height; int quality, num_coeffs; int swap_buf_size = buf_size - MIMIC_HEADER_SIZE; if(buf_size < MIMIC_HEADER_SIZE) { av_log(avctx, AV_LOG_ERROR, "insufficient data\n"); return -1; } buf += 2; /* some constant (always 256) */ quality = bytestream_get_le16(&buf); width = bytestream_get_le16(&buf); height = bytestream_get_le16(&buf); buf += 4; /* some constant */ is_pframe = bytestream_get_le32(&buf); num_coeffs = bytestream_get_byte(&buf); buf += 3; /* some constant */ if(!ctx->avctx) { int i; if(!(width == 160 && height == 120) && !(width == 320 && height == 240)) { av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n"); return -1; } ctx->avctx = avctx; avctx->width = width; avctx->height = height; avctx->pix_fmt = PIX_FMT_YUV420P; for(i = 0; i < 3; i++) { ctx->num_vblocks[i] = -((-height) >> (3 + !!i)); ctx->num_hblocks[i] = width >> (3 + !!i) ; } } else if(width != ctx->avctx->width || height != ctx->avctx->height) { av_log(avctx, AV_LOG_ERROR, "resolution changing is not supported\n"); return -1; } if(is_pframe && !ctx->buf_ptrs[ctx->prev_index].data[0]) { av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n"); return -1; } ctx->buf_ptrs[ctx->cur_index].reference = 1; if(avctx->get_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index])) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index], (AVPicture*) &ctx->buf_ptrs[ctx->cur_index]); av_fast_malloc(&ctx->swap_buf, &ctx->swap_buf_size, swap_buf_size + FF_INPUT_BUFFER_PADDING_SIZE); if(!ctx->swap_buf) return AVERROR(ENOMEM); ctx->dsp.bswap_buf(ctx->swap_buf, (const uint32_t*) buf, swap_buf_size>>2); init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3); if(!decode(ctx, quality, num_coeffs, !is_pframe)) { avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]); return -1; } ctx->buf_ptrs[ctx->cur_index].pict_type = is_pframe ? FF_P_TYPE:FF_I_TYPE; *(AVFrame*)data = ctx->buf_ptrs[ctx->cur_index]; *data_size = sizeof(AVFrame); ctx->prev_index = ctx->cur_index; ctx->cur_index--; ctx->cur_index &= 15; /* Only release frames that aren't used for backreferences anymore */ if(ctx->buf_ptrs[ctx->cur_index].data[0]) avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]); return buf_size; } static av_cold int mimic_decode_end(AVCodecContext *avctx) { MimicContext *ctx = avctx->priv_data; int i; av_free(ctx->swap_buf); for(i = 0; i < 16; i++) if(ctx->buf_ptrs[i].data[0]) avctx->release_buffer(avctx, &ctx->buf_ptrs[i]); free_vlc(&ctx->vlc); return 0; } AVCodec mimic_decoder = { "mimic", AVMEDIA_TYPE_VIDEO, CODEC_ID_MIMIC, sizeof(MimicContext), mimic_decode_init, NULL, mimic_decode_end, mimic_decode_frame, CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("Mimic"), };