/*
  * MJPEG encoder

  * Copyright (c) 2000, 2001 Fabrice Bellard

  * Copyright (c) 2003 Alex Beregszaszi
  * Copyright (c) 2003-2004 Michael Niedermayer
  *

  * Support for external huffman table, various fixes (AVID workaround),
  * aspecting, new decode_frame mechanism and apple mjpeg-b support
  *                                  by 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
  */
 
 /**

  * @file

  * MJPEG encoder.
  */
 

 #include "libavutil/pixdesc.h"
 

 #include "avcodec.h"

 #include "jpegtables.h"

 #include "mjpegenc_common.h"

 #include "mpegvideo.h"
 #include "mjpeg.h"

 #include "mjpegenc.h"

 static int alloc_huffman(MpegEncContext *s)
 {
     MJpegContext *m = s->mjpeg_ctx;
     size_t num_mbs, num_blocks, num_codes;
     int blocks_per_mb;
 
     // We need to init this here as the mjpeg init is called before the common init,
     s->mb_width  = (s->width  + 15) / 16;
     s->mb_height = (s->height + 15) / 16;
 
     switch (s->chroma_format) {
     case CHROMA_420: blocks_per_mb =  6; break;
     case CHROMA_422: blocks_per_mb =  8; break;
     case CHROMA_444: blocks_per_mb = 12; break;
     default: av_assert0(0);
     };
 
     // Make sure we have enough space to hold this frame.
     num_mbs = s->mb_width * s->mb_height;
     num_blocks = num_mbs * blocks_per_mb;
     num_codes = num_blocks * 64;
 
     m->huff_buffer = av_malloc_array(num_codes, sizeof(MJpegHuffmanCode));
     if (!m->huff_buffer)
         return AVERROR(ENOMEM);
     return 0;
 }
 

 av_cold int ff_mjpeg_encode_init(MpegEncContext *s)

 {
     MJpegContext *m;
 

     av_assert0(s->slice_context_count == 1);
 

     if (s->width > 65500 || s->height > 65500) {
         av_log(s, AV_LOG_ERROR, "JPEG does not support resolutions above 65500x65500\n");

         return AVERROR(EINVAL);

     }
 

     m = av_mallocz(sizeof(MJpegContext));

     if (!m)

         return AVERROR(ENOMEM);

 
     s->min_qcoeff=-1023;
     s->max_qcoeff= 1023;
 

     // Build default Huffman tables.
     // These may be overwritten later with more optimal Huffman tables, but
     // they are needed at least right now for some processes like trellis.

     ff_mjpeg_build_huffman_codes(m->huff_size_dc_luminance,
                                  m->huff_code_dc_luminance,

                                  avpriv_mjpeg_bits_dc_luminance,
                                  avpriv_mjpeg_val_dc);

     ff_mjpeg_build_huffman_codes(m->huff_size_dc_chrominance,
                                  m->huff_code_dc_chrominance,

                                  avpriv_mjpeg_bits_dc_chrominance,
                                  avpriv_mjpeg_val_dc);

     ff_mjpeg_build_huffman_codes(m->huff_size_ac_luminance,
                                  m->huff_code_ac_luminance,

                                  avpriv_mjpeg_bits_ac_luminance,
                                  avpriv_mjpeg_val_ac_luminance);

     ff_mjpeg_build_huffman_codes(m->huff_size_ac_chrominance,
                                  m->huff_code_ac_chrominance,

                                  avpriv_mjpeg_bits_ac_chrominance,
                                  avpriv_mjpeg_val_ac_chrominance);

     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;
 
     // Buffers start out empty.
     m->huff_ncode = 0;

     s->mjpeg_ctx = m;

     if(s->huffman == HUFFMAN_TABLE_OPTIMAL)
         return alloc_huffman(s);
 
     return 0;

 }
 

 av_cold void ff_mjpeg_encode_close(MpegEncContext *s)

 {

     av_freep(&s->mjpeg_ctx->huff_buffer);

     av_freep(&s->mjpeg_ctx);

 }
 

 /**
  * Add code and table_id to the JPEG buffer.
  *
  * @param s The MJpegContext which contains the JPEG buffer.
  * @param table_id Which Huffman table the code belongs to.
  * @param code The encoded exponent of the coefficients and the run-bits.
  */
 static inline void ff_mjpeg_encode_code(MJpegContext *s, uint8_t table_id, int code)
 {
     MJpegHuffmanCode *c = &s->huff_buffer[s->huff_ncode++];
     c->table_id = table_id;
     c->code = code;
 }
 
 /**
  * Add the coefficient's data to the JPEG buffer.
  *
  * @param s The MJpegContext which contains the JPEG buffer.
  * @param table_id Which Huffman table the code belongs to.
  * @param val The coefficient.
  * @param run The run-bits.
  */
 static void ff_mjpeg_encode_coef(MJpegContext *s, uint8_t table_id, int val, int run)
 {
     int mant, code;
 
     if (val == 0) {
         av_assert0(run == 0);
         ff_mjpeg_encode_code(s, table_id, 0);
     } else {
         mant = val;
         if (val < 0) {
             val = -val;
             mant--;
         }
 
         code = (run << 4) | (av_log2_16bit(val) + 1);
 
         s->huff_buffer[s->huff_ncode].mant = mant;
         ff_mjpeg_encode_code(s, table_id, code);
     }
 }
 
 /**
  * Add the block's data into the JPEG buffer.
  *
  * @param s The MJpegEncContext that contains the JPEG buffer.
  * @param block The block.
  * @param n The block's index or number.
  */

 static void record_block(MpegEncContext *s, int16_t *block, int n)

 {

     int i, j, table_id;
     int component, dc, last_index, val, run;

     MJpegContext *m = s->mjpeg_ctx;

     /* DC coef */
     component = (n <= 3 ? 0 : (n&1) + 1);

     table_id = (n <= 3 ? 0 : 1);

     dc = block[0]; /* overflow is impossible */
     val = dc - s->last_dc[component];

 
     ff_mjpeg_encode_coef(m, table_id, val, 0);
 

     s->last_dc[component] = dc;
 
     /* AC coefs */
 
     run = 0;
     last_index = s->block_last_index[n];

     table_id |= 2;
 

     for(i=1;i<=last_index;i++) {
         j = s->intra_scantable.permutated[i];
         val = block[j];

         if (val == 0) {
             run++;
         } else {
             while (run >= 16) {

                 ff_mjpeg_encode_code(m, table_id, 0xf0);

                 run -= 16;
             }

             ff_mjpeg_encode_coef(m, table_id, val, run);

             run = 0;
         }
     }
 
     /* output EOB only if not already 64 values */
     if (last_index < 63 || run != 0)

         ff_mjpeg_encode_code(m, table_id, 0);

 }
 

 static void encode_block(MpegEncContext *s, int16_t *block, int n)
 {
     int mant, nbits, code, i, j;
     int component, dc, run, last_index, val;
     MJpegContext *m = s->mjpeg_ctx;
     uint8_t *huff_size_ac;
     uint16_t *huff_code_ac;
 
     /* DC coef */
     component = (n <= 3 ? 0 : (n&1) + 1);
     dc = block[0]; /* overflow is impossible */
     val = dc - s->last_dc[component];
     if (n < 4) {
         ff_mjpeg_encode_dc(&s->pb, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);
         huff_size_ac = m->huff_size_ac_luminance;
         huff_code_ac = m->huff_code_ac_luminance;
     } else {
         ff_mjpeg_encode_dc(&s->pb, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
         huff_size_ac = m->huff_size_ac_chrominance;
         huff_code_ac = m->huff_code_ac_chrominance;
     }
     s->last_dc[component] = dc;
 
     /* AC coefs */
 
     run = 0;
     last_index = s->block_last_index[n];
     for(i=1;i<=last_index;i++) {
         j = s->intra_scantable.permutated[i];
         val = block[j];
         if (val == 0) {
             run++;
         } else {
             while (run >= 16) {
                 put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
                 run -= 16;
             }
             mant = val;
             if (val < 0) {
                 val = -val;
                 mant--;
             }
 
             nbits= av_log2_16bit(val) + 1;
             code = (run << 4) | nbits;
 
             put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
 
             put_sbits(&s->pb, nbits, mant);
             run = 0;
         }
     }
 
     /* output EOB only if not already 64 values */
     if (last_index < 63 || run != 0)
         put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
 }
 

 void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64])

 {

     int i;

     if (s->huffman == HUFFMAN_TABLE_OPTIMAL) {
         if (s->chroma_format == CHROMA_444) {
             record_block(s, block[0], 0);
             record_block(s, block[2], 2);
             record_block(s, block[4], 4);
             record_block(s, block[8], 8);
             record_block(s, block[5], 5);
             record_block(s, block[9], 9);
 
             if (16*s->mb_x+8 < s->width) {
                 record_block(s, block[1], 1);
                 record_block(s, block[3], 3);
                 record_block(s, block[6], 6);
                 record_block(s, block[10], 10);
                 record_block(s, block[7], 7);
                 record_block(s, block[11], 11);
             }
         } else {
             for(i=0;i<5;i++) {
                 record_block(s, block[i], i);
             }
             if (s->chroma_format == CHROMA_420) {
                 record_block(s, block[5], 5);
             } else {
                 record_block(s, block[6], 6);
                 record_block(s, block[5], 5);
                 record_block(s, block[7], 7);
             }

         }

     } else {

         if (s->chroma_format == CHROMA_444) {
             encode_block(s, block[0], 0);
             encode_block(s, block[2], 2);
             encode_block(s, block[4], 4);
             encode_block(s, block[8], 8);

             encode_block(s, block[5], 5);

             encode_block(s, block[9], 9);
 
             if (16*s->mb_x+8 < s->width) {
                 encode_block(s, block[1], 1);
                 encode_block(s, block[3], 3);
                 encode_block(s, block[6], 6);
                 encode_block(s, block[10], 10);
                 encode_block(s, block[7], 7);
                 encode_block(s, block[11], 11);
             }

         } else {

             for(i=0;i<5;i++) {
                 encode_block(s, block[i], i);
             }
             if (s->chroma_format == CHROMA_420) {
                 encode_block(s, block[5], 5);
             } else {
                 encode_block(s, block[6], 6);
                 encode_block(s, block[5], 5);
                 encode_block(s, block[7], 7);
             }

         }

 
         s->i_tex_bits += get_bits_diff(s);

     }
 }

 #if CONFIG_AMV_ENCODER

 // maximum over s->mjpeg_vsample[i]
 #define V_MAX 2

 static int amv_encode_picture(AVCodecContext *avctx, AVPacket *pkt,

                               const AVFrame *pic_arg, int *got_packet)

 {

     MpegEncContext *s = avctx->priv_data;

     AVFrame *pic;
     int i, ret;

     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->height & 15) && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {

         av_log(avctx, AV_LOG_ERROR,

                "Heights which are not a multiple of 16 might fail with some decoders, "
                "use vstrict=-1 / -strict -1 to use %d anyway.\n", avctx->height);
         av_log(avctx, AV_LOG_WARNING, "If you have a device that plays AMV videos, please test if videos "
                "with such heights work with it and report your findings to ffmpeg-devel@ffmpeg.org\n");
         return AVERROR_EXPERIMENTAL;

     }
 

     pic = av_frame_clone(pic_arg);

     if (!pic)
         return AVERROR(ENOMEM);

     //picture should be flipped upside-down
     for(i=0; i < 3; i++) {

         int vsample = i ? 2 >> chroma_v_shift : 2;

         pic->data[i] += pic->linesize[i] * (vsample * s->height / V_MAX - 1);

         pic->linesize[i] *= -1;

     }

     ret = ff_mpv_encode_picture(avctx, pkt, pic, got_packet);

     av_frame_free(&pic);
     return ret;

 }

 #endif

 #define OFFSET(x) offsetof(MpegEncContext, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {

 FF_MPV_COMMON_OPTS

 { "pred", "Prediction method", OFFSET(pred), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 3, VE, "pred" },
     { "left",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, INT_MIN, INT_MAX, VE, "pred" },
     { "plane",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 2 }, INT_MIN, INT_MAX, VE, "pred" },
     { "median", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 3 }, INT_MIN, INT_MAX, VE, "pred" },

 { "huffman", "Huffman table strategy", OFFSET(huffman), AV_OPT_TYPE_INT, { .i64 = HUFFMAN_TABLE_OPTIMAL }, 0, NB_HUFFMAN_TABLE_OPTION - 1, VE, "huffman" },

     { "default", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = HUFFMAN_TABLE_DEFAULT }, INT_MIN, INT_MAX, VE, "huffman" },
     { "optimal", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = HUFFMAN_TABLE_OPTIMAL }, INT_MIN, INT_MAX, VE, "huffman" },

 { NULL},

 };
 

 #if CONFIG_MJPEG_ENCODER

 static const AVClass mjpeg_class = {
     .class_name = "mjpeg encoder",
     .item_name  = av_default_item_name,

     .option     = options,

     .version    = LIBAVUTIL_VERSION_INT,
 };

 AVCodec ff_mjpeg_encoder = {

     .name           = "mjpeg",

     .long_name      = NULL_IF_CONFIG_SMALL("MJPEG (Motion JPEG)"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_MJPEG,

     .priv_data_size = sizeof(MpegEncContext),

     .init           = ff_mpv_encode_init,
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,

     .capabilities   = AV_CODEC_CAP_SLICE_THREADS | AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_INTRA_ONLY,

     .pix_fmts       = (const enum AVPixelFormat[]) {

         AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_NONE

     },

     .priv_class     = &mjpeg_class,

 };

 #endif

 #if CONFIG_AMV_ENCODER

 static const AVClass amv_class = {
     .class_name = "amv encoder",
     .item_name  = av_default_item_name,

     .option     = options,

     .version    = LIBAVUTIL_VERSION_INT,
 };

 AVCodec ff_amv_encoder = {

     .name           = "amv",

     .long_name      = NULL_IF_CONFIG_SMALL("AMV Video"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_AMV,

     .priv_data_size = sizeof(MpegEncContext),

     .init           = ff_mpv_encode_init,

     .encode2        = amv_encode_picture,

     .close          = ff_mpv_encode_end,

     .pix_fmts       = (const enum AVPixelFormat[]) {

         AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_NONE

     },

     .priv_class     = &amv_class,

 };

 #endif