Libav 0.7.1
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00001 /* 00002 * Bitmap Brothers JV video decoder 00003 * Copyright (c) 2011 Peter Ross <pross@xvid.org> 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00028 #include "avcodec.h" 00029 #include "dsputil.h" 00030 #include "get_bits.h" 00031 #include "libavutil/intreadwrite.h" 00032 00033 typedef struct JvContext { 00034 DSPContext dsp; 00035 AVFrame frame; 00036 uint32_t palette[AVPALETTE_COUNT]; 00037 int palette_has_changed; 00038 } JvContext; 00039 00040 static av_cold int decode_init(AVCodecContext *avctx) 00041 { 00042 JvContext *s = avctx->priv_data; 00043 avctx->pix_fmt = PIX_FMT_PAL8; 00044 dsputil_init(&s->dsp, avctx); 00045 return 0; 00046 } 00047 00051 static inline void decode2x2(GetBitContext *gb, uint8_t *dst, int linesize) 00052 { 00053 int i, j, v[2]; 00054 00055 switch (get_bits(gb, 2)) { 00056 case 1: 00057 v[0] = get_bits(gb, 8); 00058 for (j = 0; j < 2; j++) 00059 memset(dst + j*linesize, v[0], 2); 00060 break; 00061 case 2: 00062 v[0] = get_bits(gb, 8); 00063 v[1] = get_bits(gb, 8); 00064 for (j = 0; j < 2; j++) 00065 for (i = 0; i < 2; i++) 00066 dst[j*linesize + i] = v[get_bits1(gb)]; 00067 break; 00068 case 3: 00069 for (j = 0; j < 2; j++) 00070 for (i = 0; i < 2; i++) 00071 dst[j*linesize + i] = get_bits(gb, 8); 00072 } 00073 } 00074 00078 static inline void decode4x4(GetBitContext *gb, uint8_t *dst, int linesize) 00079 { 00080 int i, j, v[2]; 00081 00082 switch (get_bits(gb, 2)) { 00083 case 1: 00084 v[0] = get_bits(gb, 8); 00085 for (j = 0; j < 4; j++) 00086 memset(dst + j*linesize, v[0], 4); 00087 break; 00088 case 2: 00089 v[0] = get_bits(gb, 8); 00090 v[1] = get_bits(gb, 8); 00091 for (j = 2; j >= 0; j -= 2) { 00092 for (i = 0; i < 4; i++) 00093 dst[j*linesize + i] = v[get_bits1(gb)]; 00094 for (i = 0; i < 4; i++) 00095 dst[(j+1)*linesize + i] = v[get_bits1(gb)]; 00096 } 00097 break; 00098 case 3: 00099 for (j = 0; j < 4; j += 2) 00100 for (i = 0; i < 4; i += 2) 00101 decode2x2(gb, dst + j*linesize + i, linesize); 00102 } 00103 } 00104 00108 static inline void decode8x8(GetBitContext *gb, uint8_t *dst, int linesize, DSPContext *dsp) 00109 { 00110 int i, j, v[2]; 00111 00112 switch (get_bits(gb, 2)) { 00113 case 1: 00114 v[0] = get_bits(gb, 8); 00115 dsp->fill_block_tab[1](dst, v[0], linesize, 8); 00116 break; 00117 case 2: 00118 v[0] = get_bits(gb, 8); 00119 v[1] = get_bits(gb, 8); 00120 for (j = 7; j >= 0; j--) 00121 for (i = 0; i < 8; i++) 00122 dst[j*linesize + i] = v[get_bits1(gb)]; 00123 break; 00124 case 3: 00125 for (j = 0; j < 8; j += 4) 00126 for (i = 0; i < 8; i += 4) 00127 decode4x4(gb, dst + j*linesize + i, linesize); 00128 } 00129 } 00130 00131 static int decode_frame(AVCodecContext *avctx, 00132 void *data, int *data_size, 00133 AVPacket *avpkt) 00134 { 00135 JvContext *s = avctx->priv_data; 00136 int buf_size = avpkt->size; 00137 const uint8_t *buf = avpkt->data; 00138 const uint8_t *buf_end = buf + buf_size; 00139 int video_size, video_type, i, j; 00140 00141 video_size = AV_RL32(buf); 00142 video_type = buf[4]; 00143 buf += 5; 00144 00145 if (video_size) { 00146 if (avctx->reget_buffer(avctx, &s->frame) < 0) { 00147 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00148 return -1; 00149 } 00150 00151 if (video_type == 0 || video_type == 1) { 00152 GetBitContext gb; 00153 init_get_bits(&gb, buf, FFMIN(video_size, (buf_end - buf) * 8)); 00154 00155 for (j = 0; j < avctx->height; j += 8) 00156 for (i = 0; i < avctx->width; i += 8) 00157 decode8x8(&gb, s->frame.data[0] + j*s->frame.linesize[0] + i, 00158 s->frame.linesize[0], &s->dsp); 00159 00160 buf += video_size; 00161 } else if (video_type == 2) { 00162 if (buf + 1 <= buf_end) { 00163 int v = *buf++; 00164 for (j = 0; j < avctx->height; j++) 00165 memset(s->frame.data[0] + j*s->frame.linesize[0], v, avctx->width); 00166 } 00167 } else { 00168 av_log(avctx, AV_LOG_WARNING, "unsupported frame type %i\n", video_type); 00169 return AVERROR_INVALIDDATA; 00170 } 00171 } 00172 00173 if (buf < buf_end) { 00174 for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) { 00175 s->palette[i] = AV_RB24(buf) << 2; 00176 buf += 3; 00177 } 00178 s->palette_has_changed = 1; 00179 } 00180 00181 if (video_size) { 00182 s->frame.key_frame = 1; 00183 s->frame.pict_type = AV_PICTURE_TYPE_I; 00184 s->frame.palette_has_changed = s->palette_has_changed; 00185 s->palette_has_changed = 0; 00186 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE); 00187 00188 *data_size = sizeof(AVFrame); 00189 *(AVFrame*)data = s->frame; 00190 } 00191 00192 return buf_size; 00193 } 00194 00195 static av_cold int decode_close(AVCodecContext *avctx) 00196 { 00197 JvContext *s = avctx->priv_data; 00198 00199 if(s->frame.data[0]) 00200 avctx->release_buffer(avctx, &s->frame); 00201 00202 return 0; 00203 } 00204 00205 AVCodec ff_jv_decoder = { 00206 .name = "jv", 00207 .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"), 00208 .type = AVMEDIA_TYPE_VIDEO, 00209 .id = CODEC_ID_JV, 00210 .priv_data_size = sizeof(JvContext), 00211 .init = decode_init, 00212 .close = decode_close, 00213 .decode = decode_frame, 00214 .capabilities = CODEC_CAP_DR1, 00215 };