/*
  * lossless JPEG shared bits

  * Copyright (c) 2000, 2001 Fabrice Bellard
  * Copyright (c) 2003 Alex Beregszaszi

  *

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <stdint.h>
 #include <string.h>
 
 #include "libavutil/common.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/pixfmt.h"
 
 #include "avcodec.h"

 #include "idctdsp.h"

 #include "jpegtables.h"

 #include "put_bits.h"

 #include "mjpegenc.h"

 #include "mjpegenc_common.h"

 #include "mjpegenc_huffman.h"

 #include "mjpeg.h"
 

 av_cold void ff_init_uni_ac_vlc(const uint8_t huff_size_ac[256], uint8_t *uni_ac_vlc_len)

 {
     int i;
 
     for (i = 0; i < 128; i++) {
         int level = i - 64;
         int run;
         if (!level)
             continue;
         for (run = 0; run < 64; run++) {
             int len, code, nbits;
             int alevel = FFABS(level);
 
             len = (run >> 4) * huff_size_ac[0xf0];
 
             nbits= av_log2_16bit(alevel) + 1;
             code = ((15&run) << 4) | nbits;
 
             len += huff_size_ac[code] + nbits;
 
             uni_ac_vlc_len[UNI_AC_ENC_INDEX(run, i)] = len;
             // We ignore EOB as its just a constant which does not change generally
         }
     }
 }
 

 /* table_class: 0 = DC coef, 1 = AC coefs */
 static int put_huffman_table(PutBitContext *p, int table_class, int table_id,
                              const uint8_t *bits_table, const uint8_t *value_table)
 {
     int n, i;
 
     put_bits(p, 4, table_class);
     put_bits(p, 4, table_id);
 
     n = 0;
     for(i=1;i<=16;i++) {
         n += bits_table[i];
         put_bits(p, 8, bits_table[i]);
     }
 
     for(i=0;i<n;i++)
         put_bits(p, 8, value_table[i]);
 
     return n + 17;
 }
 

 static void jpeg_table_header(AVCodecContext *avctx, PutBitContext *p,
                               ScanTable *intra_scantable,
                               uint16_t luma_intra_matrix[64],
                               uint16_t chroma_intra_matrix[64],
                               int hsample[3])

 {
     int i, j, size;
     uint8_t *ptr;

     MpegEncContext *s = NULL;
 
     /* Since avctx->priv_data will point to LJpegEncContext in this case */
     if (avctx->codec_id != AV_CODEC_ID_LJPEG)
         s = avctx->priv_data;

     if (avctx->codec_id != AV_CODEC_ID_LJPEG) {
         int matrix_count = 1 + !!memcmp(luma_intra_matrix,
                                         chroma_intra_matrix,
                                         sizeof(luma_intra_matrix[0]) * 64);

     if (s && s->force_duplicated_matrix)

         matrix_count = 2;

     /* quant matrixes */
     put_marker(p, DQT);

     put_bits(p, 16, 2 + matrix_count * (1 + 64));

     put_bits(p, 4, 0); /* 8 bit precision */
     put_bits(p, 4, 0); /* table 0 */
     for(i=0;i<64;i++) {
         j = intra_scantable->permutated[i];

         put_bits(p, 8, luma_intra_matrix[j]);
     }
 
         if (matrix_count > 1) {
             put_bits(p, 4, 0); /* 8 bit precision */
             put_bits(p, 4, 1); /* table 1 */
             for(i=0;i<64;i++) {
                 j = intra_scantable->permutated[i];
                 put_bits(p, 8, chroma_intra_matrix[j]);
             }
         }
     }
 
     if(avctx->active_thread_type & FF_THREAD_SLICE){
         put_marker(p, DRI);
         put_bits(p, 16, 4);
         put_bits(p, 16, (avctx->width-1)/(8*hsample[0]) + 1);

     }
 
     /* huffman table */
     put_marker(p, DHT);
     flush_put_bits(p);
     ptr = put_bits_ptr(p);
     put_bits(p, 16, 0); /* patched later */
     size = 2;

 
     // Only MJPEG can have a variable Huffman variable. All other
     // formats use the default Huffman table.

     if (s && s->huffman == HUFFMAN_TABLE_OPTIMAL) {

         size += put_huffman_table(p, 0, 0, s->mjpeg_ctx->bits_dc_luminance,
                                   s->mjpeg_ctx->val_dc_luminance);
         size += put_huffman_table(p, 0, 1, s->mjpeg_ctx->bits_dc_chrominance,
                                   s->mjpeg_ctx->val_dc_chrominance);
 
         size += put_huffman_table(p, 1, 0, s->mjpeg_ctx->bits_ac_luminance,
                                   s->mjpeg_ctx->val_ac_luminance);
         size += put_huffman_table(p, 1, 1, s->mjpeg_ctx->bits_ac_chrominance,
                                   s->mjpeg_ctx->val_ac_chrominance);
     } else {
         size += put_huffman_table(p, 0, 0, avpriv_mjpeg_bits_dc_luminance,
                                   avpriv_mjpeg_val_dc);
         size += put_huffman_table(p, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
                                   avpriv_mjpeg_val_dc);
 
         size += put_huffman_table(p, 1, 0, avpriv_mjpeg_bits_ac_luminance,
                                   avpriv_mjpeg_val_ac_luminance);
         size += put_huffman_table(p, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
                                   avpriv_mjpeg_val_ac_chrominance);
     }

     AV_WB16(ptr, size);
 }
 
 static void jpeg_put_comments(AVCodecContext *avctx, PutBitContext *p)
 {
     int size;
     uint8_t *ptr;
 
     if (avctx->sample_aspect_ratio.num > 0 && avctx->sample_aspect_ratio.den > 0) {

         AVRational sar = avctx->sample_aspect_ratio;
 
         if (sar.num > 65535 || sar.den > 65535) {
             if (!av_reduce(&sar.num, &sar.den, avctx->sample_aspect_ratio.num, avctx->sample_aspect_ratio.den, 65535))
                 av_log(avctx, AV_LOG_WARNING,
                     "Cannot store exact aspect ratio %d:%d\n",
                     avctx->sample_aspect_ratio.num,
                     avctx->sample_aspect_ratio.den);
         }
 

         /* JFIF header */
         put_marker(p, APP0);
         put_bits(p, 16, 16);
         avpriv_put_string(p, "JFIF", 1); /* this puts the trailing zero-byte too */

         /* The most significant byte is used for major revisions, the least
          * significant byte for minor revisions. Version 1.02 is the current
          * released revision. */
         put_bits(p, 16, 0x0102);

         put_bits(p,  8, 0);              /* units type: 0 - aspect ratio */

         put_bits(p, 16, sar.num);
         put_bits(p, 16, sar.den);

         put_bits(p, 8, 0); /* thumbnail width */
         put_bits(p, 8, 0); /* thumbnail height */
     }
 
     /* comment */

     if (!(avctx->flags & AV_CODEC_FLAG_BITEXACT)) {

         put_marker(p, COM);
         flush_put_bits(p);
         ptr = put_bits_ptr(p);
         put_bits(p, 16, 0); /* patched later */
         avpriv_put_string(p, LIBAVCODEC_IDENT, 1);
         size = strlen(LIBAVCODEC_IDENT)+3;
         AV_WB16(ptr, size);
     }
 

     if (((avctx->pix_fmt == AV_PIX_FMT_YUV420P ||
           avctx->pix_fmt == AV_PIX_FMT_YUV422P ||
           avctx->pix_fmt == AV_PIX_FMT_YUV444P) && avctx->color_range != AVCOL_RANGE_JPEG)
         || avctx->color_range == AVCOL_RANGE_MPEG) {

         put_marker(p, COM);
         flush_put_bits(p);
         ptr = put_bits_ptr(p);
         put_bits(p, 16, 0); /* patched later */
         avpriv_put_string(p, "CS=ITU601", 1);
         size = strlen("CS=ITU601")+3;
         AV_WB16(ptr, size);
     }
 }
 

 void ff_mjpeg_init_hvsample(AVCodecContext *avctx, int hsample[4], int vsample[4])

 {
     int chroma_h_shift, chroma_v_shift;
 
     av_pix_fmt_get_chroma_sub_sample(avctx->pix_fmt, &chroma_h_shift,
                                      &chroma_v_shift);
     if (avctx->codec->id == AV_CODEC_ID_LJPEG &&

         (   avctx->pix_fmt == AV_PIX_FMT_BGR0
          || avctx->pix_fmt == AV_PIX_FMT_BGRA
          || avctx->pix_fmt == AV_PIX_FMT_BGR24)) {

         vsample[0] = hsample[0] =
         vsample[1] = hsample[1] =

         vsample[2] = hsample[2] =
         vsample[3] = hsample[3] = 1;

     } else if (avctx->pix_fmt == AV_PIX_FMT_YUV444P || avctx->pix_fmt == AV_PIX_FMT_YUVJ444P) {
         vsample[0] = vsample[1] = vsample[2] = 2;
         hsample[0] = hsample[1] = hsample[2] = 1;

     } else {
         vsample[0] = 2;
         vsample[1] = 2 >> chroma_v_shift;
         vsample[2] = 2 >> chroma_v_shift;
         hsample[0] = 2;
         hsample[1] = 2 >> chroma_h_shift;
         hsample[2] = 2 >> chroma_h_shift;
     }

 }
 
 void ff_mjpeg_encode_picture_header(AVCodecContext *avctx, PutBitContext *pb,

                                     ScanTable *intra_scantable, int pred,

                                     uint16_t luma_intra_matrix[64],
                                     uint16_t chroma_intra_matrix[64])
 {
     const int lossless = avctx->codec_id != AV_CODEC_ID_MJPEG && avctx->codec_id != AV_CODEC_ID_AMV;

     int hsample[4], vsample[4];

     int i;

     int components = 3 + (avctx->pix_fmt == AV_PIX_FMT_BGRA);

     int chroma_matrix = !!memcmp(luma_intra_matrix,
                                  chroma_intra_matrix,
                                  sizeof(luma_intra_matrix[0])*64);
 
     ff_mjpeg_init_hvsample(avctx, hsample, vsample);

 
     put_marker(pb, SOI);
 

     // hack for AMV mjpeg format
     if(avctx->codec_id == AV_CODEC_ID_AMV) goto end;
 

     jpeg_put_comments(avctx, pb);
 

     jpeg_table_header(avctx, pb, intra_scantable, luma_intra_matrix, chroma_intra_matrix, hsample);

 
     switch (avctx->codec_id) {
     case AV_CODEC_ID_MJPEG:  put_marker(pb, SOF0 ); break;
     case AV_CODEC_ID_LJPEG:  put_marker(pb, SOF3 ); break;

     default: av_assert0(0);

     }
 
     put_bits(pb, 16, 17);

     if (lossless && (  avctx->pix_fmt == AV_PIX_FMT_BGR0
                     || avctx->pix_fmt == AV_PIX_FMT_BGRA
                     || avctx->pix_fmt == AV_PIX_FMT_BGR24))

         put_bits(pb, 8, 9); /* 9 bits/component RCT */
     else
         put_bits(pb, 8, 8); /* 8 bits/component */
     put_bits(pb, 16, avctx->height);
     put_bits(pb, 16, avctx->width);

     put_bits(pb, 8, components); /* 3 or 4 components */

 
     /* Y component */
     put_bits(pb, 8, 1); /* component number */
     put_bits(pb, 4, hsample[0]); /* H factor */
     put_bits(pb, 4, vsample[0]); /* V factor */
     put_bits(pb, 8, 0); /* select matrix */
 
     /* Cb component */
     put_bits(pb, 8, 2); /* component number */
     put_bits(pb, 4, hsample[1]); /* H factor */
     put_bits(pb, 4, vsample[1]); /* V factor */

     put_bits(pb, 8, lossless ? 0 : chroma_matrix); /* select matrix */

 
     /* Cr component */
     put_bits(pb, 8, 3); /* component number */
     put_bits(pb, 4, hsample[2]); /* H factor */
     put_bits(pb, 4, vsample[2]); /* V factor */

     put_bits(pb, 8, lossless ? 0 : chroma_matrix); /* select matrix */

     if (components == 4) {
         put_bits(pb, 8, 4); /* component number */
         put_bits(pb, 4, hsample[3]); /* H factor */
         put_bits(pb, 4, vsample[3]); /* V factor */
         put_bits(pb, 8, 0); /* select matrix */
     }
 

     /* scan header */
     put_marker(pb, SOS);

     put_bits(pb, 16, 6 + 2*components); /* length */
     put_bits(pb, 8, components); /* 3 components */

 
     /* Y component */
     put_bits(pb, 8, 1); /* index */
     put_bits(pb, 4, 0); /* DC huffman table index */
     put_bits(pb, 4, 0); /* AC huffman table index */
 
     /* Cb component */
     put_bits(pb, 8, 2); /* index */
     put_bits(pb, 4, 1); /* DC huffman table index */
     put_bits(pb, 4, lossless ? 0 : 1); /* AC huffman table index */
 
     /* Cr component */
     put_bits(pb, 8, 3); /* index */
     put_bits(pb, 4, 1); /* DC huffman table index */
     put_bits(pb, 4, lossless ? 0 : 1); /* AC huffman table index */
 

     if (components == 4) {
         /* Alpha component */
         put_bits(pb, 8, 4); /* index */
         put_bits(pb, 4, 0); /* DC huffman table index */
         put_bits(pb, 4, 0); /* AC huffman table index */
     }
 

     put_bits(pb, 8, lossless ? pred : 0); /* Ss (not used) */

 
     switch (avctx->codec_id) {
     case AV_CODEC_ID_MJPEG:  put_bits(pb, 8, 63); break; /* Se (not used) */
     case AV_CODEC_ID_LJPEG:  put_bits(pb, 8,  0); break; /* not used */

     default: av_assert0(0);

     }
 
     put_bits(pb, 8, 0); /* Ah/Al (not used) */

 
 end:
     if (!lossless) {
         MpegEncContext *s = avctx->priv_data;
         av_assert0(avctx->codec->priv_data_size == sizeof(MpegEncContext));
 
         s->esc_pos = put_bits_count(pb) >> 3;
         for(i=1; i<s->slice_context_count; i++)
             s->thread_context[i]->esc_pos = 0;
     }

 }
 

 /**
  * Encodes and outputs the entire frame in the JPEG format.
  *
  * @param s The MpegEncContext.
  */
 void ff_mjpeg_encode_picture_frame(MpegEncContext *s)
 {
     int i, nbits, code, table_id;
     MJpegContext *m = s->mjpeg_ctx;
     uint8_t *huff_size[4] = {m->huff_size_dc_luminance,
                              m->huff_size_dc_chrominance,
                              m->huff_size_ac_luminance,
                              m->huff_size_ac_chrominance};
     uint16_t *huff_code[4] = {m->huff_code_dc_luminance,
                               m->huff_code_dc_chrominance,
                               m->huff_code_ac_luminance,
                               m->huff_code_ac_chrominance};
     size_t total_bits = 0;
     size_t bytes_needed;
 
     s->header_bits = get_bits_diff(s);
     // Estimate the total size first
     for (i = 0; i < m->huff_ncode; i++) {
         table_id = m->huff_buffer[i].table_id;
         code = m->huff_buffer[i].code;
         nbits = code & 0xf;
 
         total_bits += huff_size[table_id][code] + nbits;
     }
 
     bytes_needed = (total_bits + 7) / 8;
     ff_mpv_reallocate_putbitbuffer(s, bytes_needed, bytes_needed);
 
     for (i = 0; i < m->huff_ncode; i++) {
         table_id = m->huff_buffer[i].table_id;
         code = m->huff_buffer[i].code;
         nbits = code & 0xf;
 
         put_bits(&s->pb, huff_size[table_id][code], huff_code[table_id][code]);
         if (nbits != 0) {
             put_sbits(&s->pb, nbits, m->huff_buffer[i].mant);
         }
     }
 
     m->huff_ncode = 0;
     s->i_tex_bits = get_bits_diff(s);
 }
 

 void ff_mjpeg_escape_FF(PutBitContext *pb, int start)

 {

     int size;

     int i, ff_count;
     uint8_t *buf = pb->buf + start;
     int align= (-(size_t)(buf))&3;

     int pad = (-put_bits_count(pb))&7;
 
     if (pad)
         put_bits(pb, pad, (1<<pad)-1);

     flush_put_bits(pb);
     size = put_bits_count(pb) - start * 8;
 
     av_assert1((size&7) == 0);

     size >>= 3;
 
     ff_count=0;
     for(i=0; i<size && i<align; i++){
         if(buf[i]==0xFF) ff_count++;
     }
     for(; i<size-15; i+=16){
         int acc, v;
 
         v= *(uint32_t*)(&buf[i]);
         acc= (((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
         v= *(uint32_t*)(&buf[i+4]);
         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
         v= *(uint32_t*)(&buf[i+8]);
         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
         v= *(uint32_t*)(&buf[i+12]);
         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
 
         acc>>=4;
         acc+= (acc>>16);
         acc+= (acc>>8);
         ff_count+= acc&0xFF;
     }
     for(; i<size; i++){
         if(buf[i]==0xFF) ff_count++;
     }
 
     if(ff_count==0) return;
 
     flush_put_bits(pb);
     skip_put_bytes(pb, ff_count);
 
     for(i=size-1; ff_count; i--){
         int v= buf[i];
 
         if(v==0xFF){
             buf[i+ff_count]= 0;
             ff_count--;
         }
 
         buf[i+ff_count]= v;
     }
 }
 

 /**
  * Builds all 4 optimal Huffman tables.
  *
  * Uses the data stored in the JPEG buffer to compute the tables.
  * Stores the Huffman tables in the bits_* and val_* arrays in the MJpegContext.
  *
  * @param m MJpegContext containing the JPEG buffer.
  */
 static void ff_mjpeg_build_optimal_huffman(MJpegContext *m)
 {

     int i, table_id, code;

 
     MJpegEncHuffmanContext dc_luminance_ctx;
     MJpegEncHuffmanContext dc_chrominance_ctx;
     MJpegEncHuffmanContext ac_luminance_ctx;
     MJpegEncHuffmanContext ac_chrominance_ctx;
     MJpegEncHuffmanContext *ctx[4] = {&dc_luminance_ctx,
                                       &dc_chrominance_ctx,
                                       &ac_luminance_ctx,
                                       &ac_chrominance_ctx};
     for (i = 0; i < 4; i++) {
         ff_mjpeg_encode_huffman_init(ctx[i]);
     }
     for (i = 0; i < m->huff_ncode; i++) {
         table_id = m->huff_buffer[i].table_id;
         code = m->huff_buffer[i].code;
 
         ff_mjpeg_encode_huffman_increment(ctx[table_id], code);
     }
 

     ff_mjpeg_encode_huffman_close(&dc_luminance_ctx,
                                   m->bits_dc_luminance,
                                   m->val_dc_luminance, 12);
     ff_mjpeg_encode_huffman_close(&dc_chrominance_ctx,
                                   m->bits_dc_chrominance,
                                   m->val_dc_chrominance, 12);
     ff_mjpeg_encode_huffman_close(&ac_luminance_ctx,
                                   m->bits_ac_luminance,
                                   m->val_ac_luminance, 256);
     ff_mjpeg_encode_huffman_close(&ac_chrominance_ctx,
                                   m->bits_ac_chrominance,
                                   m->val_ac_chrominance, 256);

 
     ff_mjpeg_build_huffman_codes(m->huff_size_dc_luminance,
                                  m->huff_code_dc_luminance,
                                  m->bits_dc_luminance,
                                  m->val_dc_luminance);
     ff_mjpeg_build_huffman_codes(m->huff_size_dc_chrominance,
                                  m->huff_code_dc_chrominance,
                                  m->bits_dc_chrominance,
                                  m->val_dc_chrominance);
     ff_mjpeg_build_huffman_codes(m->huff_size_ac_luminance,
                                  m->huff_code_ac_luminance,
                                  m->bits_ac_luminance,
                                  m->val_ac_luminance);
     ff_mjpeg_build_huffman_codes(m->huff_size_ac_chrominance,
                                  m->huff_code_ac_chrominance,
                                  m->bits_ac_chrominance,
                                  m->val_ac_chrominance);
 }
 
 /**

  * Writes the complete JPEG frame when optimal huffman tables are enabled,
  * otherwise writes the stuffing.

  *
  * Header + values + stuffing.
  *
  * @param s The MpegEncContext.
  * @return int Error code, 0 if successful.
  */

 int ff_mjpeg_encode_stuffing(MpegEncContext *s)

 {

     int i;
     PutBitContext *pbc = &s->pb;
     int mb_y = s->mb_y - !s->mb_x;

     int ret;
     MJpegContext *m;
 
     m = s->mjpeg_ctx;
 
     if (s->huffman == HUFFMAN_TABLE_OPTIMAL) {
         ff_mjpeg_build_optimal_huffman(m);
 
         // Replace the VLCs with the optimal ones.
         // The default ones may be used for trellis during quantization.

         ff_init_uni_ac_vlc(m->huff_size_ac_luminance,   m->uni_ac_vlc_len);
         ff_init_uni_ac_vlc(m->huff_size_ac_chrominance, m->uni_chroma_ac_vlc_len);

         s->intra_ac_vlc_length      =
         s->intra_ac_vlc_last_length = m->uni_ac_vlc_len;
         s->intra_chroma_ac_vlc_length      =
         s->intra_chroma_ac_vlc_last_length = m->uni_chroma_ac_vlc_len;
 

         ff_mjpeg_encode_picture_header(s->avctx, &s->pb, &s->intra_scantable,
                                        s->pred, s->intra_matrix, s->chroma_intra_matrix);
         ff_mjpeg_encode_picture_frame(s);
     }

 
     ret = ff_mpv_reallocate_putbitbuffer(s, put_bits_count(&s->pb) / 8 + 100,
                                             put_bits_count(&s->pb) / 4 + 1000);

     if (ret < 0) {
         av_log(s->avctx, AV_LOG_ERROR, "Buffer reallocation failed\n");
         goto fail;
     }
 

     ff_mjpeg_escape_FF(pbc, s->esc_pos);
 
     if((s->avctx->active_thread_type & FF_THREAD_SLICE) && mb_y < s->mb_height)
         put_marker(pbc, RST0 + (mb_y&7));
     s->esc_pos = put_bits_count(pbc) >> 3;

 fail:

 
     for(i=0; i<3; i++)
         s->last_dc[i] = 128 << s->intra_dc_precision;

 
     return ret;

 }
 
 void ff_mjpeg_encode_picture_trailer(PutBitContext *pb, int header_bits)
 {

     av_assert1((header_bits & 7) == 0);

 
     put_marker(pb, EOI);
 }
 
 void ff_mjpeg_encode_dc(PutBitContext *pb, int val,
                         uint8_t *huff_size, uint16_t *huff_code)
 {
     int mant, nbits;
 
     if (val == 0) {
         put_bits(pb, huff_size[0], huff_code[0]);
     } else {
         mant = val;
         if (val < 0) {
             val = -val;
             mant--;
         }
 
         nbits= av_log2_16bit(val) + 1;
 
         put_bits(pb, huff_size[nbits], huff_code[nbits]);
 
         put_sbits(pb, nbits, mant);
     }
 }