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00029 #include "libavutil/common.h"
00030 #include "avcodec.h"
00031 #include "bytestream.h"
00032
00033 typedef struct BFIContext {
00034 AVCodecContext *avctx;
00035 AVFrame frame;
00036 uint8_t *dst;
00037 } BFIContext;
00038
00039 static av_cold int bfi_decode_init(AVCodecContext *avctx)
00040 {
00041 BFIContext *bfi = avctx->priv_data;
00042 avctx->pix_fmt = PIX_FMT_PAL8;
00043 bfi->dst = av_mallocz(avctx->width * avctx->height);
00044 return 0;
00045 }
00046
00047 static int bfi_decode_frame(AVCodecContext *avctx, void *data,
00048 int *data_size, AVPacket *avpkt)
00049 {
00050 GetByteContext g;
00051 int buf_size = avpkt->size;
00052 BFIContext *bfi = avctx->priv_data;
00053 uint8_t *dst = bfi->dst;
00054 uint8_t *src, *dst_offset, colour1, colour2;
00055 uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
00056 uint32_t *pal;
00057 int i, j, height = avctx->height;
00058
00059 if (bfi->frame.data[0])
00060 avctx->release_buffer(avctx, &bfi->frame);
00061
00062 bfi->frame.reference = 1;
00063
00064 if (avctx->get_buffer(avctx, &bfi->frame) < 0) {
00065 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00066 return -1;
00067 }
00068
00069 bytestream2_init(&g, avpkt->data, buf_size);
00070
00071
00072 if (!avctx->frame_number) {
00073 bfi->frame.pict_type = AV_PICTURE_TYPE_I;
00074 bfi->frame.key_frame = 1;
00075
00076 if (avctx->extradata_size > 768) {
00077 av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
00078 return -1;
00079 }
00080 pal = (uint32_t *)bfi->frame.data[1];
00081 for (i = 0; i < avctx->extradata_size / 3; i++) {
00082 int shift = 16;
00083 *pal = 0;
00084 for (j = 0; j < 3; j++, shift -= 8)
00085 *pal +=
00086 ((avctx->extradata[i * 3 + j] << 2) |
00087 (avctx->extradata[i * 3 + j] >> 4)) << shift;
00088 pal++;
00089 }
00090 bfi->frame.palette_has_changed = 1;
00091 } else {
00092 bfi->frame.pict_type = AV_PICTURE_TYPE_P;
00093 bfi->frame.key_frame = 0;
00094 }
00095
00096 bytestream2_skip(&g, 4);
00097
00098 while (dst != frame_end) {
00099 static const uint8_t lentab[4] = { 0, 2, 0, 1 };
00100 unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
00101 unsigned int code = byte >> 6;
00102 unsigned int length = byte & ~0xC0;
00103
00104 if (!bytestream2_get_bytes_left(&g)) {
00105 av_log(avctx, AV_LOG_ERROR,
00106 "Input resolution larger than actual frame.\n");
00107 return -1;
00108 }
00109
00110
00111 if (length == 0) {
00112 if (code == 1) {
00113 length = bytestream2_get_byte(&g);
00114 offset = bytestream2_get_le16(&g);
00115 } else {
00116 length = bytestream2_get_le16(&g);
00117 if (code == 2 && length == 0)
00118 break;
00119 }
00120 } else {
00121 if (code == 1)
00122 offset = bytestream2_get_byte(&g);
00123 }
00124
00125
00126 if (dst + (length << lentab[code]) > frame_end)
00127 break;
00128
00129 switch (code) {
00130
00131 case 0:
00132 if (length >= bytestream2_get_bytes_left(&g)) {
00133 av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
00134 return -1;
00135 }
00136 bytestream2_get_buffer(&g, dst, length);
00137 dst += length;
00138 break;
00139
00140 case 1:
00141 dst_offset = dst - offset;
00142 length *= 4;
00143 if (dst_offset < bfi->dst)
00144 break;
00145 while (length--)
00146 *dst++ = *dst_offset++;
00147 break;
00148
00149 case 2:
00150 dst += length;
00151 break;
00152
00153 case 3:
00154 colour1 = bytestream2_get_byte(&g);
00155 colour2 = bytestream2_get_byte(&g);
00156 while (length--) {
00157 *dst++ = colour1;
00158 *dst++ = colour2;
00159 }
00160 break;
00161
00162 }
00163 }
00164
00165 src = bfi->dst;
00166 dst = bfi->frame.data[0];
00167 while (height--) {
00168 memcpy(dst, src, avctx->width);
00169 src += avctx->width;
00170 dst += bfi->frame.linesize[0];
00171 }
00172 *data_size = sizeof(AVFrame);
00173 *(AVFrame *)data = bfi->frame;
00174 return buf_size;
00175 }
00176
00177 static av_cold int bfi_decode_close(AVCodecContext * avctx)
00178 {
00179 BFIContext *bfi = avctx->priv_data;
00180 if (bfi->frame.data[0])
00181 avctx->release_buffer(avctx, &bfi->frame);
00182 av_free(bfi->dst);
00183 return 0;
00184 }
00185
00186 AVCodec ff_bfi_decoder = {
00187 .name = "bfi",
00188 .type = AVMEDIA_TYPE_VIDEO,
00189 .id = CODEC_ID_BFI,
00190 .priv_data_size = sizeof(BFIContext),
00191 .init = bfi_decode_init,
00192 .close = bfi_decode_close,
00193 .decode = bfi_decode_frame,
00194 .capabilities = CODEC_CAP_DR1,
00195 .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
00196 };