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libavcodec/dnxhddec.c

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00001 /*
00002  * VC3/DNxHD decoder.
00003  * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 //#define TRACE
00023 //#define DEBUG
00024 
00025 #include "avcodec.h"
00026 #include "bitstream.h"
00027 #include "dnxhddata.h"
00028 #include "dsputil.h"
00029 
00030 typedef struct {
00031     AVCodecContext *avctx;
00032     AVFrame picture;
00033     GetBitContext gb;
00034     int cid;                            
00035     unsigned int width, height;
00036     unsigned int mb_width, mb_height;
00037     uint32_t mb_scan_index[68];         /* max for 1080p */
00038     int cur_field;                      
00039     VLC ac_vlc, dc_vlc, run_vlc;
00040     int last_dc[3];
00041     DSPContext dsp;
00042     DECLARE_ALIGNED_16(DCTELEM, blocks[8][64]);
00043     DECLARE_ALIGNED_8(ScanTable, scantable);
00044     const CIDEntry *cid_table;
00045 } DNXHDContext;
00046 
00047 #define DNXHD_VLC_BITS 9
00048 #define DNXHD_DC_VLC_BITS 7
00049 
00050 static av_cold int dnxhd_decode_init(AVCodecContext *avctx)
00051 {
00052     DNXHDContext *ctx = avctx->priv_data;
00053 
00054     ctx->avctx = avctx;
00055     dsputil_init(&ctx->dsp, avctx);
00056     avctx->coded_frame = &ctx->picture;
00057     ctx->picture.type = FF_I_TYPE;
00058     return 0;
00059 }
00060 
00061 static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
00062 {
00063     if (!ctx->cid_table) {
00064         int index;
00065 
00066         if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {
00067             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
00068             return -1;
00069         }
00070         ctx->cid_table = &ff_dnxhd_cid_table[index];
00071         init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
00072                  ctx->cid_table->ac_bits, 1, 1,
00073                  ctx->cid_table->ac_codes, 2, 2, 0);
00074         init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->cid_table->bit_depth+4,
00075                  ctx->cid_table->dc_bits, 1, 1,
00076                  ctx->cid_table->dc_codes, 1, 1, 0);
00077         init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
00078                  ctx->cid_table->run_bits, 1, 1,
00079                  ctx->cid_table->run_codes, 2, 2, 0);
00080 
00081         ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, ff_zigzag_direct);
00082     }
00083     return 0;
00084 }
00085 
00086 static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)
00087 {
00088     static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
00089     int i;
00090 
00091     if (buf_size < 0x280)
00092         return -1;
00093 
00094     if (memcmp(buf, header_prefix, 5)) {
00095         av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
00096         return -1;
00097     }
00098     if (buf[5] & 2) { /* interlaced */
00099         ctx->cur_field = buf[5] & 1;
00100         ctx->picture.interlaced_frame = 1;
00101         ctx->picture.top_field_first = first_field ^ ctx->cur_field;
00102         av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);
00103     }
00104 
00105     ctx->height = AV_RB16(buf + 0x18);
00106     ctx->width  = AV_RB16(buf + 0x1a);
00107 
00108     dprintf(ctx->avctx, "width %d, heigth %d\n", ctx->width, ctx->height);
00109 
00110     if (buf[0x21] & 0x40) {
00111         av_log(ctx->avctx, AV_LOG_ERROR, "10 bit per component\n");
00112         return -1;
00113     }
00114 
00115     ctx->cid = AV_RB32(buf + 0x28);
00116     dprintf(ctx->avctx, "compression id %d\n", ctx->cid);
00117 
00118     if (dnxhd_init_vlc(ctx, ctx->cid) < 0)
00119         return -1;
00120 
00121     if (buf_size < ctx->cid_table->coding_unit_size) {
00122         av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
00123         return -1;
00124     }
00125 
00126     ctx->mb_width = ctx->width>>4;
00127     ctx->mb_height = buf[0x16d];
00128 
00129     if (ctx->mb_height > 68) {
00130         av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big\n");
00131         return -1;
00132     }
00133 
00134     dprintf(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
00135     for (i = 0; i < ctx->mb_height; i++) {
00136         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));
00137         dprintf(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);
00138         if (buf_size < ctx->mb_scan_index[i] + 0x280) {
00139             av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
00140             return -1;
00141         }
00142     }
00143 
00144     return 0;
00145 }
00146 
00147 static int dnxhd_decode_dc(DNXHDContext *ctx)
00148 {
00149     int len;
00150 
00151     len = get_vlc2(&ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
00152     return len ? get_xbits(&ctx->gb, len) : 0;
00153 }
00154 
00155 static void dnxhd_decode_dct_block(DNXHDContext *ctx, DCTELEM *block, int n, int qscale)
00156 {
00157     int i, j, index, index2;
00158     int level, component, sign;
00159     const uint8_t *weigth_matrix;
00160 
00161     if (n&2) {
00162         component = 1 + (n&1);
00163         weigth_matrix = ctx->cid_table->chroma_weight;
00164     } else {
00165         component = 0;
00166         weigth_matrix = ctx->cid_table->luma_weight;
00167     }
00168 
00169     ctx->last_dc[component] += dnxhd_decode_dc(ctx);
00170     block[0] = ctx->last_dc[component];
00171     //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
00172     for (i = 1; ; i++) {
00173         index = get_vlc2(&ctx->gb, ctx->ac_vlc.table, DNXHD_VLC_BITS, 2);
00174         //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index);
00175         level = ctx->cid_table->ac_level[index];
00176         if (!level) { /* EOB */
00177             //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
00178             return;
00179         }
00180         sign = get_sbits(&ctx->gb, 1);
00181 
00182         if (ctx->cid_table->ac_index_flag[index]) {
00183             level += get_bits(&ctx->gb, ctx->cid_table->index_bits)<<6;
00184         }
00185 
00186         if (ctx->cid_table->ac_run_flag[index]) {
00187             index2 = get_vlc2(&ctx->gb, ctx->run_vlc.table, DNXHD_VLC_BITS, 2);
00188             i += ctx->cid_table->run[index2];
00189         }
00190 
00191         if (i > 63) {
00192             av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
00193             return;
00194         }
00195 
00196         j = ctx->scantable.permutated[i];
00197         //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
00198         //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weigth %d\n", level, weigth_matrix[i]);
00199         level = (2*level+1) * qscale * weigth_matrix[i];
00200         if (ctx->cid_table->bit_depth == 10) {
00201             if (weigth_matrix[i] != 8)
00202                 level += 8;
00203             level >>= 4;
00204         } else {
00205             if (weigth_matrix[i] != 32)
00206                 level += 32;
00207             level >>= 6;
00208         }
00209         //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);
00210         block[j] = (level^sign) - sign;
00211     }
00212 }
00213 
00214 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
00215 {
00216     int dct_linesize_luma   = ctx->picture.linesize[0];
00217     int dct_linesize_chroma = ctx->picture.linesize[1];
00218     uint8_t *dest_y, *dest_u, *dest_v;
00219     int dct_offset;
00220     int qscale, i;
00221 
00222     qscale = get_bits(&ctx->gb, 11);
00223     skip_bits1(&ctx->gb);
00224     //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
00225 
00226     for (i = 0; i < 8; i++) {
00227         ctx->dsp.clear_block(ctx->blocks[i]);
00228         dnxhd_decode_dct_block(ctx, ctx->blocks[i], i, qscale);
00229     }
00230 
00231     if (ctx->picture.interlaced_frame) {
00232         dct_linesize_luma   <<= 1;
00233         dct_linesize_chroma <<= 1;
00234     }
00235 
00236     dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << 4);
00237     dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << 3);
00238     dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << 3);
00239 
00240     if (ctx->cur_field) {
00241         dest_y += ctx->picture.linesize[0];
00242         dest_u += ctx->picture.linesize[1];
00243         dest_v += ctx->picture.linesize[2];
00244     }
00245 
00246     dct_offset = dct_linesize_luma << 3;
00247     ctx->dsp.idct_put(dest_y,                  dct_linesize_luma, ctx->blocks[0]);
00248     ctx->dsp.idct_put(dest_y + 8,              dct_linesize_luma, ctx->blocks[1]);
00249     ctx->dsp.idct_put(dest_y + dct_offset,     dct_linesize_luma, ctx->blocks[4]);
00250     ctx->dsp.idct_put(dest_y + dct_offset + 8, dct_linesize_luma, ctx->blocks[5]);
00251 
00252     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
00253         dct_offset = dct_linesize_chroma << 3;
00254         ctx->dsp.idct_put(dest_u,              dct_linesize_chroma, ctx->blocks[2]);
00255         ctx->dsp.idct_put(dest_v,              dct_linesize_chroma, ctx->blocks[3]);
00256         ctx->dsp.idct_put(dest_u + dct_offset, dct_linesize_chroma, ctx->blocks[6]);
00257         ctx->dsp.idct_put(dest_v + dct_offset, dct_linesize_chroma, ctx->blocks[7]);
00258     }
00259 
00260     return 0;
00261 }
00262 
00263 static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)
00264 {
00265     int x, y;
00266     for (y = 0; y < ctx->mb_height; y++) {
00267         ctx->last_dc[0] =
00268         ctx->last_dc[1] =
00269         ctx->last_dc[2] = 1<<(ctx->cid_table->bit_depth+2); // for levels +2^(bitdepth-1)
00270         init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
00271         for (x = 0; x < ctx->mb_width; x++) {
00272             //START_TIMER;
00273             dnxhd_decode_macroblock(ctx, x, y);
00274             //STOP_TIMER("decode macroblock");
00275         }
00276     }
00277     return 0;
00278 }
00279 
00280 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
00281                               const uint8_t *buf, int buf_size)
00282 {
00283     DNXHDContext *ctx = avctx->priv_data;
00284     AVFrame *picture = data;
00285     int first_field = 1;
00286 
00287     dprintf(avctx, "frame size %d\n", buf_size);
00288 
00289  decode_coding_unit:
00290     if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)
00291         return -1;
00292 
00293     avctx->pix_fmt = PIX_FMT_YUV422P;
00294     if (avcodec_check_dimensions(avctx, ctx->width, ctx->height))
00295         return -1;
00296     avcodec_set_dimensions(avctx, ctx->width, ctx->height);
00297 
00298     if (first_field) {
00299         if (ctx->picture.data[0])
00300             avctx->release_buffer(avctx, &ctx->picture);
00301         if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
00302             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00303             return -1;
00304         }
00305     }
00306 
00307     dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
00308 
00309     if (first_field && ctx->picture.interlaced_frame) {
00310         buf      += ctx->cid_table->coding_unit_size;
00311         buf_size -= ctx->cid_table->coding_unit_size;
00312         first_field = 0;
00313         goto decode_coding_unit;
00314     }
00315 
00316     *picture = ctx->picture;
00317     *data_size = sizeof(AVPicture);
00318     return buf_size;
00319 }
00320 
00321 static av_cold int dnxhd_decode_close(AVCodecContext *avctx)
00322 {
00323     DNXHDContext *ctx = avctx->priv_data;
00324 
00325     if (ctx->picture.data[0])
00326         avctx->release_buffer(avctx, &ctx->picture);
00327     free_vlc(&ctx->ac_vlc);
00328     free_vlc(&ctx->dc_vlc);
00329     free_vlc(&ctx->run_vlc);
00330     return 0;
00331 }
00332 
00333 AVCodec dnxhd_decoder = {
00334     "dnxhd",
00335     CODEC_TYPE_VIDEO,
00336     CODEC_ID_DNXHD,
00337     sizeof(DNXHDContext),
00338     dnxhd_decode_init,
00339     NULL,
00340     dnxhd_decode_close,
00341     dnxhd_decode_frame,
00342     CODEC_CAP_DR1,
00343     .long_name = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),
00344 };

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