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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 "libavutil/imgutils.h"
00026 #include "avcodec.h"
00027 #include "get_bits.h"
00028 #include "dnxhddata.h"
00029 #include "dsputil.h"
00030 
00031 typedef struct {
00032     AVCodecContext *avctx;
00033     AVFrame picture;
00034     GetBitContext gb;
00035     int cid;                            
00036     unsigned int width, height;
00037     unsigned int mb_width, mb_height;
00038     uint32_t mb_scan_index[68];         /* max for 1080p */
00039     int cur_field;                      
00040     VLC ac_vlc, dc_vlc, run_vlc;
00041     int last_dc[3];
00042     DSPContext dsp;
00043     DECLARE_ALIGNED(16, DCTELEM, blocks)[8][64];
00044     ScanTable scantable;
00045     const CIDEntry *cid_table;
00046 } DNXHDContext;
00047 
00048 #define DNXHD_VLC_BITS 9
00049 #define DNXHD_DC_VLC_BITS 7
00050 
00051 static av_cold int dnxhd_decode_init(AVCodecContext *avctx)
00052 {
00053     DNXHDContext *ctx = avctx->priv_data;
00054 
00055     ctx->avctx = avctx;
00056     dsputil_init(&ctx->dsp, avctx);
00057     avctx->coded_frame = &ctx->picture;
00058     avcodec_get_frame_defaults(&ctx->picture);
00059     ctx->picture.type = AV_PICTURE_TYPE_I;
00060     ctx->picture.key_frame = 1;
00061     return 0;
00062 }
00063 
00064 static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
00065 {
00066     if (!ctx->cid_table) {
00067         int index;
00068 
00069         if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {
00070             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
00071             return -1;
00072         }
00073         ctx->cid_table = &ff_dnxhd_cid_table[index];
00074         init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
00075                  ctx->cid_table->ac_bits, 1, 1,
00076                  ctx->cid_table->ac_codes, 2, 2, 0);
00077         init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->cid_table->bit_depth+4,
00078                  ctx->cid_table->dc_bits, 1, 1,
00079                  ctx->cid_table->dc_codes, 1, 1, 0);
00080         init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
00081                  ctx->cid_table->run_bits, 1, 1,
00082                  ctx->cid_table->run_codes, 2, 2, 0);
00083 
00084         ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, ff_zigzag_direct);
00085     }
00086     return 0;
00087 }
00088 
00089 static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)
00090 {
00091     static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
00092     int i;
00093 
00094     if (buf_size < 0x280)
00095         return -1;
00096 
00097     if (memcmp(buf, header_prefix, 5)) {
00098         av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
00099         return -1;
00100     }
00101     if (buf[5] & 2) { /* interlaced */
00102         ctx->cur_field = buf[5] & 1;
00103         ctx->picture.interlaced_frame = 1;
00104         ctx->picture.top_field_first = first_field ^ ctx->cur_field;
00105         av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);
00106     }
00107 
00108     ctx->height = AV_RB16(buf + 0x18);
00109     ctx->width  = AV_RB16(buf + 0x1a);
00110 
00111     av_dlog(ctx->avctx, "width %d, heigth %d\n", ctx->width, ctx->height);
00112 
00113     if (buf[0x21] & 0x40) {
00114         av_log(ctx->avctx, AV_LOG_ERROR, "10 bit per component\n");
00115         return -1;
00116     }
00117 
00118     ctx->cid = AV_RB32(buf + 0x28);
00119     av_dlog(ctx->avctx, "compression id %d\n", ctx->cid);
00120 
00121     if (dnxhd_init_vlc(ctx, ctx->cid) < 0)
00122         return -1;
00123 
00124     if (buf_size < ctx->cid_table->coding_unit_size) {
00125         av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
00126         return -1;
00127     }
00128 
00129     ctx->mb_width = ctx->width>>4;
00130     ctx->mb_height = buf[0x16d];
00131 
00132     av_dlog(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
00133 
00134     if ((ctx->height+15)>>4 == ctx->mb_height && ctx->picture.interlaced_frame)
00135         ctx->height <<= 1;
00136 
00137     if (ctx->mb_height > 68 ||
00138         (ctx->mb_height<<ctx->picture.interlaced_frame) > (ctx->height+15)>>4) {
00139         av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big: %d\n", ctx->mb_height);
00140         return -1;
00141     }
00142 
00143     for (i = 0; i < ctx->mb_height; i++) {
00144         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));
00145         av_dlog(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);
00146         if (buf_size < ctx->mb_scan_index[i] + 0x280) {
00147             av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
00148             return -1;
00149         }
00150     }
00151 
00152     return 0;
00153 }
00154 
00155 static int dnxhd_decode_dc(DNXHDContext *ctx)
00156 {
00157     int len;
00158 
00159     len = get_vlc2(&ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
00160     return len ? get_xbits(&ctx->gb, len) : 0;
00161 }
00162 
00163 static void dnxhd_decode_dct_block(DNXHDContext *ctx, DCTELEM *block, int n, int qscale)
00164 {
00165     int i, j, index, index2;
00166     int level, component, sign;
00167     const uint8_t *weigth_matrix;
00168 
00169     if (n&2) {
00170         component = 1 + (n&1);
00171         weigth_matrix = ctx->cid_table->chroma_weight;
00172     } else {
00173         component = 0;
00174         weigth_matrix = ctx->cid_table->luma_weight;
00175     }
00176 
00177     ctx->last_dc[component] += dnxhd_decode_dc(ctx);
00178     block[0] = ctx->last_dc[component];
00179     //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
00180     for (i = 1; ; i++) {
00181         index = get_vlc2(&ctx->gb, ctx->ac_vlc.table, DNXHD_VLC_BITS, 2);
00182         //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index);
00183         level = ctx->cid_table->ac_level[index];
00184         if (!level) { /* EOB */
00185             //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
00186             return;
00187         }
00188         sign = get_sbits(&ctx->gb, 1);
00189 
00190         if (ctx->cid_table->ac_index_flag[index]) {
00191             level += get_bits(&ctx->gb, ctx->cid_table->index_bits)<<6;
00192         }
00193 
00194         if (ctx->cid_table->ac_run_flag[index]) {
00195             index2 = get_vlc2(&ctx->gb, ctx->run_vlc.table, DNXHD_VLC_BITS, 2);
00196             i += ctx->cid_table->run[index2];
00197         }
00198 
00199         if (i > 63) {
00200             av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
00201             return;
00202         }
00203 
00204         j = ctx->scantable.permutated[i];
00205         //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
00206         //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weigth %d\n", level, weigth_matrix[i]);
00207         level = (2*level+1) * qscale * weigth_matrix[i];
00208         if (ctx->cid_table->bit_depth == 10) {
00209             if (weigth_matrix[i] != 8)
00210                 level += 8;
00211             level >>= 4;
00212         } else {
00213             if (weigth_matrix[i] != 32)
00214                 level += 32;
00215             level >>= 6;
00216         }
00217         //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);
00218         block[j] = (level^sign) - sign;
00219     }
00220 }
00221 
00222 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
00223 {
00224     int dct_linesize_luma   = ctx->picture.linesize[0];
00225     int dct_linesize_chroma = ctx->picture.linesize[1];
00226     uint8_t *dest_y, *dest_u, *dest_v;
00227     int dct_offset;
00228     int qscale, i;
00229 
00230     qscale = get_bits(&ctx->gb, 11);
00231     skip_bits1(&ctx->gb);
00232     //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
00233 
00234     for (i = 0; i < 8; i++) {
00235         ctx->dsp.clear_block(ctx->blocks[i]);
00236         dnxhd_decode_dct_block(ctx, ctx->blocks[i], i, qscale);
00237     }
00238 
00239     if (ctx->picture.interlaced_frame) {
00240         dct_linesize_luma   <<= 1;
00241         dct_linesize_chroma <<= 1;
00242     }
00243 
00244     dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << 4);
00245     dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << 3);
00246     dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << 3);
00247 
00248     if (ctx->cur_field) {
00249         dest_y += ctx->picture.linesize[0];
00250         dest_u += ctx->picture.linesize[1];
00251         dest_v += ctx->picture.linesize[2];
00252     }
00253 
00254     dct_offset = dct_linesize_luma << 3;
00255     ctx->dsp.idct_put(dest_y,                  dct_linesize_luma, ctx->blocks[0]);
00256     ctx->dsp.idct_put(dest_y + 8,              dct_linesize_luma, ctx->blocks[1]);
00257     ctx->dsp.idct_put(dest_y + dct_offset,     dct_linesize_luma, ctx->blocks[4]);
00258     ctx->dsp.idct_put(dest_y + dct_offset + 8, dct_linesize_luma, ctx->blocks[5]);
00259 
00260     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
00261         dct_offset = dct_linesize_chroma << 3;
00262         ctx->dsp.idct_put(dest_u,              dct_linesize_chroma, ctx->blocks[2]);
00263         ctx->dsp.idct_put(dest_v,              dct_linesize_chroma, ctx->blocks[3]);
00264         ctx->dsp.idct_put(dest_u + dct_offset, dct_linesize_chroma, ctx->blocks[6]);
00265         ctx->dsp.idct_put(dest_v + dct_offset, dct_linesize_chroma, ctx->blocks[7]);
00266     }
00267 
00268     return 0;
00269 }
00270 
00271 static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)
00272 {
00273     int x, y;
00274     for (y = 0; y < ctx->mb_height; y++) {
00275         ctx->last_dc[0] =
00276         ctx->last_dc[1] =
00277         ctx->last_dc[2] = 1<<(ctx->cid_table->bit_depth+2); // for levels +2^(bitdepth-1)
00278         init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
00279         for (x = 0; x < ctx->mb_width; x++) {
00280             //START_TIMER;
00281             dnxhd_decode_macroblock(ctx, x, y);
00282             //STOP_TIMER("decode macroblock");
00283         }
00284     }
00285     return 0;
00286 }
00287 
00288 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
00289                               AVPacket *avpkt)
00290 {
00291     const uint8_t *buf = avpkt->data;
00292     int buf_size = avpkt->size;
00293     DNXHDContext *ctx = avctx->priv_data;
00294     AVFrame *picture = data;
00295     int first_field = 1;
00296 
00297     av_dlog(avctx, "frame size %d\n", buf_size);
00298 
00299  decode_coding_unit:
00300     if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)
00301         return -1;
00302 
00303     if ((avctx->width || avctx->height) &&
00304         (ctx->width != avctx->width || ctx->height != avctx->height)) {
00305         av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %dx%d\n",
00306                avctx->width, avctx->height, ctx->width, ctx->height);
00307         first_field = 1;
00308     }
00309 
00310     avctx->pix_fmt = PIX_FMT_YUV422P;
00311     if (av_image_check_size(ctx->width, ctx->height, 0, avctx))
00312         return -1;
00313     avcodec_set_dimensions(avctx, ctx->width, ctx->height);
00314 
00315     if (first_field) {
00316         if (ctx->picture.data[0])
00317             avctx->release_buffer(avctx, &ctx->picture);
00318         if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
00319             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00320             return -1;
00321         }
00322     }
00323 
00324     dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
00325 
00326     if (first_field && ctx->picture.interlaced_frame) {
00327         buf      += ctx->cid_table->coding_unit_size;
00328         buf_size -= ctx->cid_table->coding_unit_size;
00329         first_field = 0;
00330         goto decode_coding_unit;
00331     }
00332 
00333     *picture = ctx->picture;
00334     *data_size = sizeof(AVPicture);
00335     return buf_size;
00336 }
00337 
00338 static av_cold int dnxhd_decode_close(AVCodecContext *avctx)
00339 {
00340     DNXHDContext *ctx = avctx->priv_data;
00341 
00342     if (ctx->picture.data[0])
00343         avctx->release_buffer(avctx, &ctx->picture);
00344     free_vlc(&ctx->ac_vlc);
00345     free_vlc(&ctx->dc_vlc);
00346     free_vlc(&ctx->run_vlc);
00347     return 0;
00348 }
00349 
00350 AVCodec ff_dnxhd_decoder = {
00351     "dnxhd",
00352     AVMEDIA_TYPE_VIDEO,
00353     CODEC_ID_DNXHD,
00354     sizeof(DNXHDContext),
00355     dnxhd_decode_init,
00356     NULL,
00357     dnxhd_decode_close,
00358     dnxhd_decode_frame,
00359     CODEC_CAP_DR1,
00360     .long_name = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),
00361 };

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