Libav 0.7.1
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 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 
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     ctx->picture.type = AV_PICTURE_TYPE_I;
00059     ctx->picture.key_frame = 1;
00060     return 0;
00061 }
00062 
00063 static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
00064 {
00065     if (!ctx->cid_table) {
00066         int index;
00067 
00068         if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {
00069             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
00070             return -1;
00071         }
00072         ctx->cid_table = &ff_dnxhd_cid_table[index];
00073         init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
00074                  ctx->cid_table->ac_bits, 1, 1,
00075                  ctx->cid_table->ac_codes, 2, 2, 0);
00076         init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->cid_table->bit_depth+4,
00077                  ctx->cid_table->dc_bits, 1, 1,
00078                  ctx->cid_table->dc_codes, 1, 1, 0);
00079         init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
00080                  ctx->cid_table->run_bits, 1, 1,
00081                  ctx->cid_table->run_codes, 2, 2, 0);
00082 
00083         ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, ff_zigzag_direct);
00084     }
00085     return 0;
00086 }
00087 
00088 static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)
00089 {
00090     static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
00091     int i;
00092 
00093     if (buf_size < 0x280)
00094         return -1;
00095 
00096     if (memcmp(buf, header_prefix, 5)) {
00097         av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
00098         return -1;
00099     }
00100     if (buf[5] & 2) { /* interlaced */
00101         ctx->cur_field = buf[5] & 1;
00102         ctx->picture.interlaced_frame = 1;
00103         ctx->picture.top_field_first = first_field ^ ctx->cur_field;
00104         av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);
00105     }
00106 
00107     ctx->height = AV_RB16(buf + 0x18);
00108     ctx->width  = AV_RB16(buf + 0x1a);
00109 
00110     av_dlog(ctx->avctx, "width %d, heigth %d\n", ctx->width, ctx->height);
00111 
00112     if (buf[0x21] & 0x40) {
00113         av_log(ctx->avctx, AV_LOG_ERROR, "10 bit per component\n");
00114         return -1;
00115     }
00116 
00117     ctx->cid = AV_RB32(buf + 0x28);
00118     av_dlog(ctx->avctx, "compression id %d\n", ctx->cid);
00119 
00120     if (dnxhd_init_vlc(ctx, ctx->cid) < 0)
00121         return -1;
00122 
00123     if (buf_size < ctx->cid_table->coding_unit_size) {
00124         av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
00125         return -1;
00126     }
00127 
00128     ctx->mb_width = ctx->width>>4;
00129     ctx->mb_height = buf[0x16d];
00130 
00131     av_dlog(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
00132 
00133     if ((ctx->height+15)>>4 == ctx->mb_height && ctx->picture.interlaced_frame)
00134         ctx->height <<= 1;
00135 
00136     if (ctx->mb_height > 68 ||
00137         (ctx->mb_height<<ctx->picture.interlaced_frame) > (ctx->height+15)>>4) {
00138         av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big: %d\n", ctx->mb_height);
00139         return -1;
00140     }
00141 
00142     for (i = 0; i < ctx->mb_height; i++) {
00143         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));
00144         av_dlog(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);
00145         if (buf_size < ctx->mb_scan_index[i] + 0x280) {
00146             av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
00147             return -1;
00148         }
00149     }
00150 
00151     return 0;
00152 }
00153 
00154 static int dnxhd_decode_dc(DNXHDContext *ctx)
00155 {
00156     int len;
00157 
00158     len = get_vlc2(&ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
00159     return len ? get_xbits(&ctx->gb, len) : 0;
00160 }
00161 
00162 static void dnxhd_decode_dct_block(DNXHDContext *ctx, DCTELEM *block, int n, int qscale)
00163 {
00164     int i, j, index, index2;
00165     int level, component, sign;
00166     const uint8_t *weigth_matrix;
00167 
00168     if (n&2) {
00169         component = 1 + (n&1);
00170         weigth_matrix = ctx->cid_table->chroma_weight;
00171     } else {
00172         component = 0;
00173         weigth_matrix = ctx->cid_table->luma_weight;
00174     }
00175 
00176     ctx->last_dc[component] += dnxhd_decode_dc(ctx);
00177     block[0] = ctx->last_dc[component];
00178     //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
00179     for (i = 1; ; i++) {
00180         index = get_vlc2(&ctx->gb, ctx->ac_vlc.table, DNXHD_VLC_BITS, 2);
00181         //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index);
00182         level = ctx->cid_table->ac_level[index];
00183         if (!level) { /* EOB */
00184             //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
00185             return;
00186         }
00187         sign = get_sbits(&ctx->gb, 1);
00188 
00189         if (ctx->cid_table->ac_index_flag[index]) {
00190             level += get_bits(&ctx->gb, ctx->cid_table->index_bits)<<6;
00191         }
00192 
00193         if (ctx->cid_table->ac_run_flag[index]) {
00194             index2 = get_vlc2(&ctx->gb, ctx->run_vlc.table, DNXHD_VLC_BITS, 2);
00195             i += ctx->cid_table->run[index2];
00196         }
00197 
00198         if (i > 63) {
00199             av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
00200             return;
00201         }
00202 
00203         j = ctx->scantable.permutated[i];
00204         //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
00205         //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weigth %d\n", level, weigth_matrix[i]);
00206         level = (2*level+1) * qscale * weigth_matrix[i];
00207         if (ctx->cid_table->bit_depth == 10) {
00208             if (weigth_matrix[i] != 8)
00209                 level += 8;
00210             level >>= 4;
00211         } else {
00212             if (weigth_matrix[i] != 32)
00213                 level += 32;
00214             level >>= 6;
00215         }
00216         //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);
00217         block[j] = (level^sign) - sign;
00218     }
00219 }
00220 
00221 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
00222 {
00223     int dct_linesize_luma   = ctx->picture.linesize[0];
00224     int dct_linesize_chroma = ctx->picture.linesize[1];
00225     uint8_t *dest_y, *dest_u, *dest_v;
00226     int dct_offset;
00227     int qscale, i;
00228 
00229     qscale = get_bits(&ctx->gb, 11);
00230     skip_bits1(&ctx->gb);
00231     //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
00232 
00233     for (i = 0; i < 8; i++) {
00234         ctx->dsp.clear_block(ctx->blocks[i]);
00235         dnxhd_decode_dct_block(ctx, ctx->blocks[i], i, qscale);
00236     }
00237 
00238     if (ctx->picture.interlaced_frame) {
00239         dct_linesize_luma   <<= 1;
00240         dct_linesize_chroma <<= 1;
00241     }
00242 
00243     dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << 4);
00244     dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << 3);
00245     dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << 3);
00246 
00247     if (ctx->cur_field) {
00248         dest_y += ctx->picture.linesize[0];
00249         dest_u += ctx->picture.linesize[1];
00250         dest_v += ctx->picture.linesize[2];
00251     }
00252 
00253     dct_offset = dct_linesize_luma << 3;
00254     ctx->dsp.idct_put(dest_y,                  dct_linesize_luma, ctx->blocks[0]);
00255     ctx->dsp.idct_put(dest_y + 8,              dct_linesize_luma, ctx->blocks[1]);
00256     ctx->dsp.idct_put(dest_y + dct_offset,     dct_linesize_luma, ctx->blocks[4]);
00257     ctx->dsp.idct_put(dest_y + dct_offset + 8, dct_linesize_luma, ctx->blocks[5]);
00258 
00259     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
00260         dct_offset = dct_linesize_chroma << 3;
00261         ctx->dsp.idct_put(dest_u,              dct_linesize_chroma, ctx->blocks[2]);
00262         ctx->dsp.idct_put(dest_v,              dct_linesize_chroma, ctx->blocks[3]);
00263         ctx->dsp.idct_put(dest_u + dct_offset, dct_linesize_chroma, ctx->blocks[6]);
00264         ctx->dsp.idct_put(dest_v + dct_offset, dct_linesize_chroma, ctx->blocks[7]);
00265     }
00266 
00267     return 0;
00268 }
00269 
00270 static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)
00271 {
00272     int x, y;
00273     for (y = 0; y < ctx->mb_height; y++) {
00274         ctx->last_dc[0] =
00275         ctx->last_dc[1] =
00276         ctx->last_dc[2] = 1<<(ctx->cid_table->bit_depth+2); // for levels +2^(bitdepth-1)
00277         init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
00278         for (x = 0; x < ctx->mb_width; x++) {
00279             //START_TIMER;
00280             dnxhd_decode_macroblock(ctx, x, y);
00281             //STOP_TIMER("decode macroblock");
00282         }
00283     }
00284     return 0;
00285 }
00286 
00287 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
00288                               AVPacket *avpkt)
00289 {
00290     const uint8_t *buf = avpkt->data;
00291     int buf_size = avpkt->size;
00292     DNXHDContext *ctx = avctx->priv_data;
00293     AVFrame *picture = data;
00294     int first_field = 1;
00295 
00296     av_dlog(avctx, "frame size %d\n", buf_size);
00297 
00298  decode_coding_unit:
00299     if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)
00300         return -1;
00301 
00302     if ((avctx->width || avctx->height) &&
00303         (ctx->width != avctx->width || ctx->height != avctx->height)) {
00304         av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %dx%d\n",
00305                avctx->width, avctx->height, ctx->width, ctx->height);
00306         first_field = 1;
00307     }
00308 
00309     avctx->pix_fmt = PIX_FMT_YUV422P;
00310     if (av_image_check_size(ctx->width, ctx->height, 0, avctx))
00311         return -1;
00312     avcodec_set_dimensions(avctx, ctx->width, ctx->height);
00313 
00314     if (first_field) {
00315         if (ctx->picture.data[0])
00316             avctx->release_buffer(avctx, &ctx->picture);
00317         if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
00318             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00319             return -1;
00320         }
00321     }
00322 
00323     dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
00324 
00325     if (first_field && ctx->picture.interlaced_frame) {
00326         buf      += ctx->cid_table->coding_unit_size;
00327         buf_size -= ctx->cid_table->coding_unit_size;
00328         first_field = 0;
00329         goto decode_coding_unit;
00330     }
00331 
00332     *picture = ctx->picture;
00333     *data_size = sizeof(AVPicture);
00334     return buf_size;
00335 }
00336 
00337 static av_cold int dnxhd_decode_close(AVCodecContext *avctx)
00338 {
00339     DNXHDContext *ctx = avctx->priv_data;
00340 
00341     if (ctx->picture.data[0])
00342         avctx->release_buffer(avctx, &ctx->picture);
00343     free_vlc(&ctx->ac_vlc);
00344     free_vlc(&ctx->dc_vlc);
00345     free_vlc(&ctx->run_vlc);
00346     return 0;
00347 }
00348 
00349 AVCodec ff_dnxhd_decoder = {
00350     "dnxhd",
00351     AVMEDIA_TYPE_VIDEO,
00352     CODEC_ID_DNXHD,
00353     sizeof(DNXHDContext),
00354     dnxhd_decode_init,
00355     NULL,
00356     dnxhd_decode_close,
00357     dnxhd_decode_frame,
00358     CODEC_CAP_DR1,
00359     .long_name = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),
00360 };