@@ -59,6 +59,7 @@ void avcodec_register_all(void)

 //    register_avcodec(&h264_encoder);

 #ifdef CONFIG_RISKY

     register_avcodec(&mpeg2video_encoder);

+    register_avcodec(&h261_encoder);

     register_avcodec(&h263_encoder);

     register_avcodec(&h263p_encoder);

     register_avcodec(&flv_encoder);

@@ -1786,6 +1786,7 @@ extern AVCodec faac_encoder;

 extern AVCodec xvid_encoder;

 extern AVCodec mpeg1video_encoder;

 extern AVCodec mpeg2video_encoder;

+extern AVCodec h261_encoder;

 extern AVCodec h263_encoder;

 extern AVCodec h263p_encoder;

 extern AVCodec flv_encoder;

@@ -47,6 +47,7 @@ typedef struct H261Context{

     MpegEncContext s;

     int current_mba;

+    int previous_mba;

     int mba_diff;

     int mtype;

     int current_mv_x;

@@ -76,11 +77,330 @@ void ff_h261_loop_filter(MpegEncContext *s){

     s->dsp.h261_loop_filter(dest_cr, uvlinesize);

 }

+int ff_h261_get_picture_format(int width, int height){

+    // QCIF

+    if (width == 176 && height == 144)

+        return 0;

+    // CIF

+    else if (width == 352 && height == 288)

+        return 1;

+    // ERROR

+    else

+        return -1;

+}

+

+static void h261_encode_block(H261Context * h, DCTELEM * block,

+                              int n);

 static int h261_decode_block(H261Context *h, DCTELEM *block,

                              int n, int coded);

 static int h261_decode_mb(H261Context *h);

 void ff_set_qscale(MpegEncContext * s, int qscale);

+void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){

+    H261Context * h = (H261Context *) s;

+    int format, coded_frame_rate, coded_frame_rate_base, temp_ref;

+    int best_clock_code=1;

+    int best_divisor=60;

+    coded_frame_rate= 1800000;

+    coded_frame_rate_base= (1000+best_clock_code)*best_divisor;

+

+    align_put_bits(&s->pb);

+

+    /* Update the pointer to last GOB */

+    s->ptr_lastgob = pbBufPtr(&s->pb);

+

+    put_bits(&s->pb, 20, 0x10); /* PSC */

+

+    temp_ref= s->picture_number * (int64_t)coded_frame_rate * s->avctx->frame_rate_base / 

+                         (coded_frame_rate_base * (int64_t)s->avctx->frame_rate);

+    put_bits(&s->pb, 5, temp_ref & 0x1f); /* TemporalReference */

+

+    put_bits(&s->pb, 1, 0); /* split screen off */

+    put_bits(&s->pb, 1, 0); /* camera  off */

+    put_bits(&s->pb, 1, 0); /* freeze picture release off */

+    

+    format = ff_h261_get_picture_format(s->width, s->height);

+    

+    put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */

+

+    put_bits(&s->pb, 1, 0); /* still image mode */

+    put_bits(&s->pb, 1, 0); /* reserved */

+

+    put_bits(&s->pb, 1, 0); /* no PEI */    

+    if(format == 0)

+        h->gob_number = -1;

+    else

+        h->gob_number = 0;

+    h->current_mba = 0;

+}

+

+/**

+ * Encodes a group of blocks header.

+ */

+static void h261_encode_gob_header(MpegEncContext * s, int mb_line){

+    H261Context * h = (H261Context *)s;

+    if(ff_h261_get_picture_format(s->width, s->height) == 0){

+        h->gob_number+=2; // QCIF

+    }

+    else{

+        h->gob_number++; // CIF

+    }

+    put_bits(&s->pb, 16, 1); /* GBSC */

+    put_bits(&s->pb, 4, h->gob_number); /* GN */

+    put_bits(&s->pb, 5, s->qscale); /* GQUANT */

+    put_bits(&s->pb, 1, 0); /* no GEI */

+    h->current_mba = 0;

+    h->previous_mba = 0;

+    h->current_mv_x=0;

+    h->current_mv_y=0;

+}

+

+void ff_h261_reorder_mb_index(MpegEncContext* s){

+    /* for CIF the GOB's are fragmented in the middle of a scanline

+       that's why we need to adjust the x and y index of the macroblocks */

+    if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF

+        if((s->mb_x == 0 && (s->mb_y % 3 == 0) ) || (s->mb_x == 11 && ((s->mb_y -1 )% 3 == 0) ))

+            h261_encode_gob_header(s,0);

+        if(s->mb_x < 11 ){

+            if((s->mb_y % 3) == 1 ){

+                s->mb_x += 0;

+                s->mb_y += 1;

+            }

+            else if( (s->mb_y % 3) == 2 ){

+                s->mb_x += 11;

+                s->mb_y -= 1;

+            }

+        }

+        else{

+            if((s->mb_y % 3) == 1 ){

+                s->mb_x += 0;

+                s->mb_y -= 1;

+            }

+            else if( (s->mb_y % 3) == 0 ){

+                s->mb_x -= 11;

+                s->mb_y += 1;

+            }

+        }

+        ff_init_block_index(s);

+        ff_update_block_index(s);

+    /* for QCIF we don't need to reorder MB's

+       there the GOB's aren't fragmented in the middle of a scanline */

+    }else if(ff_h261_get_picture_format(s->width,s->height) == 0){ // QCIF

+        if(s->mb_y % 3 == 0 && s->mb_x == 0)

+            h261_encode_gob_header(s,0);

+    }

+}

+

+static void h261_encode_motion(H261Context * h, int val){

+    MpegEncContext * const s = &h->s;

+    int sign, code;

+    if(val==0){

+        code = 0;

+        put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);

+    } 

+    else{

+        if(val > 16)

+            val -=32;

+        if(val < -16)

+            val+=32;

+        sign = val < 0;

+        code = sign ? -val : val; 

+        put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);

+        put_bits(&s->pb,1,sign);

+    }

+}

+

+static inline int get_cbp(MpegEncContext * s,

+                      DCTELEM block[6][64])

+{

+    int i, cbp;

+    cbp= 0;

+    for (i = 0; i < 6; i++) {

+        if (s->block_last_index[i] >= 0)

+            cbp |= 1 << (5 - i);

+    }

+    return cbp;

+}

+void ff_h261_encode_mb(MpegEncContext * s,

+         DCTELEM block[6][64],

+         int motion_x, int motion_y)

+{

+    H261Context * h = (H261Context *)s;

+    int old_mtype, mvd, mv_diff_x, mv_diff_y, i, cbp;

+    cbp = 63; // avoid warning

+    mvd = 0;

+ 

+    h->current_mba++;

+    old_mtype = h->mtype;

+    h->mtype = 0;

+ 

+    if (!s->mb_intra){

+        /* compute cbp */

+        cbp= get_cbp(s, block);

+   

+        /* mvd indicates if this block is motion compensated */

+        if(((motion_x >> 1) - h->current_mv_x != 0) || ((motion_y >> 1 ) - h->current_mv_y) != 0){

+            mvd = 1;

+        }

+        else if((motion_x >> 1 == 0) && (motion_y >> 1 == 0)){

+            mvd = 0;

+        }

+        else

+            mvd = 1;

+        if((cbp | mvd | s->dquant ) == 0) {

+            /* skip macroblock */

+            s->skip_count++;

+            h->current_mv_x=0;

+            h->current_mv_y=0;

+            return;

+        }

+    }

+

+    /* MB is not skipped, encode MBA */

+    put_bits(&s->pb, h261_mba_bits[(h->current_mba-h->previous_mba)-1], h261_mba_code[(h->current_mba-h->previous_mba)-1]);

+ 

+    /* calculate MTYPE */

+    if(!s->mb_intra){

+        h->mtype+=2;

+    if(mvd == 1){   

+        h->mtype+=2;

+        if(cbp!=0)

+            h->mtype+=1;

+        if(s->loop_filter)

+            h->mtype+=3;

+        }

+    }

+

+    if(s->dquant) 

+        h->mtype++;

+

+    put_bits(&s->pb, h261_mtype_bits[h->mtype], h261_mtype_code[h->mtype]);

+ 

+    h->mtype = h261_mtype_map[h->mtype];

+ 

+    if(IS_QUANT(h->mtype)){

+        ff_set_qscale(s,s->qscale+s->dquant);

+        put_bits(&s->pb, 5, s->qscale);

+    }

+ 

+    if(IS_16X16(h->mtype)){

+        mv_diff_x = (motion_x >> 1) - h->current_mv_x;

+        mv_diff_y = (motion_y >> 1) - h->current_mv_y;

+        h->current_mv_x = (motion_x >> 1);

+        h->current_mv_y = (motion_y >> 1);

+        h261_encode_motion(h,mv_diff_x);

+        h261_encode_motion(h,mv_diff_y);

+    }

+ 

+    h->previous_mba = h->current_mba;

+ 

+    if(HAS_CBP(h->mtype)){

+        put_bits(&s->pb,h261_cbp_tab[cbp-1][1],h261_cbp_tab[cbp-1][0]); 

+    }

+    for(i=0; i<6; i++) {

+        /* encode each block */

+        h261_encode_block(h, block[i], i);

+    }

+

+    if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){

+        h->current_mv_x=0;

+        h->current_mv_y=0;

+    }

+}

+

+void ff_h261_encode_init(MpegEncContext *s){

+    static int done = 0;

+    

+    if (!done) {

+        done = 1;

+        init_rl(&h261_rl_tcoeff);

+    }

+

+    s->min_qcoeff= -127;

+    s->max_qcoeff=  127;

+    s->y_dc_scale_table=

+    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;

+}

+

+

+/**

+ * encodes a 8x8 block.

+ * @param block the 8x8 block

+ * @param n block index (0-3 are luma, 4-5 are chroma)

+ */

+static void h261_encode_block(H261Context * h, DCTELEM * block, int n){

+    MpegEncContext * const s = &h->s;

+    int level, run, last, i, j, last_index, last_non_zero, sign, slevel, code;

+    RLTable *rl;

+

+    rl = &h261_rl_tcoeff;

+    if (s->mb_intra) {

+        /* DC coef */

+        level = block[0];

+        /* 255 cannot be represented, so we clamp */

+        if (level > 254) {

+            level = 254;

+            block[0] = 254;

+        }

+        /* 0 cannot be represented also */

+        else if (level < 1) {

+            level = 1;

+            block[0] = 1;

+        }

+        if (level == 128)

+            put_bits(&s->pb, 8, 0xff);

+        else

+            put_bits(&s->pb, 8, level);

+        i = 1;

+    } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){

+        //special case

+        put_bits(&s->pb,1,1);

+        put_bits(&s->pb,1,block[0]>0 ? 0 : 1 );

+        i = 1;

+    } else {

+        i = 0;

+    }

+   

+    /* AC coefs */

+    last_index = s->block_last_index[n];

+    last_non_zero = i - 1;

+    for (; i <= last_index; i++) {

+        j = s->intra_scantable.permutated[i];

+        level = block[j];

+        if (level) {

+            run = i - last_non_zero - 1;

+            last = (i == last_index);

+            sign = 0;

+            slevel = level;

+            if (level < 0) {

+                sign = 1;

+                level = -level;

+            }

+            code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/, run, level);

+            if(run==0 && level < 16)

+            code+=1;

+            put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);

+            if (code == rl->n) {

+                put_bits(&s->pb, 6, run);

+                assert(slevel != 0);

+                if(slevel < -127){

+                    slevel = -127;

+                }

+                else if(slevel > 127){

+                    slevel = 127;

+                }

+                put_bits(&s->pb, 8, slevel & 0xff);

+            } else {

+                put_bits(&s->pb, 1, sign);

+            }

+            last_non_zero = i;

+        }

+    }

+    if(last_index > -1){

+        put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK

+    }

+}

+

 /***********************************************/

 /* decoding */

@@ -767,6 +1087,16 @@ static int h261_decode_end(AVCodecContext *avctx)

     return 0;

 }

+AVCodec h261_encoder = {

+    "h261",

+    CODEC_TYPE_VIDEO,

+    CODEC_ID_H261,

+    sizeof(H261Context),

+    MPV_encode_init,

+    MPV_encode_picture,

+    MPV_encode_end,

+};

+

 AVCodec h261_decoder = {

     "h261",

     CODEC_TYPE_VIDEO,

@@ -88,7 +88,7 @@ static int RENAME(dct_quantize)(MpegEncContext *s,

         qmat = s->q_inter_matrix16[qscale][0];

     }

-    if(s->out_format == FMT_H263 && s->mpeg_quant==0){

+    if((s->out_format == FMT_H263 || s->out_format == FMT_H261) && s->mpeg_quant==0){

         asm volatile(

             "movd %%"REG_a", %%mm3		\n\t" // last_non_zero_p1

@@ -279,6 +279,10 @@ void ff_init_me(MpegEncContext *s){

         c->hpel_put[2][2]= c->hpel_put[2][3]= zero_hpel;

     }

+    if(s->codec_id == CODEC_ID_H261){

+        c->sub_motion_search= no_sub_motion_search;

+    }

+

     c->temp= c->scratchpad;

 }

@@ -691,6 +695,12 @@ static inline void get_limits(MpegEncContext *s, int x, int y)

         c->ymin = - y - 16;

         c->xmax = - x + s->mb_width *16;

         c->ymax = - y + s->mb_height*16;

+    } else if (s->out_format == FMT_H261){

+        // Search range of H261 is different from other codec standards

+        c->xmin = (x > 15) ? - 15 : 0;

+        c->ymin = (y > 15) ? - 15 : 0;

+        c->xmax = (x < s->mb_width * 16 - 16) ? 15 : 0;              

+        c->ymax = (y < s->mb_height * 16 - 16) ? 15 : 0;

     } else {

         c->xmin = - x;

         c->ymin = - y;

@@ -221,6 +221,16 @@ static int hpel_motion_search(MpegEncContext * s,

 }

 #endif

+static int no_sub_motion_search(MpegEncContext * s,

+          int *mx_ptr, int *my_ptr, int dmin,

+                                  int src_index, int ref_index,

+                                  int size, int h)

+{

+    (*mx_ptr)<<=1;

+    (*my_ptr)<<=1;

+    return dmin;

+}

+

 int inline ff_get_mb_score(MpegEncContext * s, int mx, int my, int src_index,

                                int ref_index, int size, int h, int add_rate)

 {

@@ -1080,6 +1080,11 @@ int MPV_encode_init(AVCodecContext *avctx)

         s->low_delay=1;

         break;

 #ifdef CONFIG_RISKY

+    case CODEC_ID_H261:

+        s->out_format = FMT_H261;

+        avctx->delay=0;

+        s->low_delay=1;

+        break;

     case CODEC_ID_H263:

         if (h263_get_picture_format(s->width, s->height) == 7) {

             av_log(avctx, AV_LOG_INFO, "Input picture size isn't suitable for h263 codec! try h263+\n");

@@ -1199,6 +1204,8 @@ int MPV_encode_init(AVCodecContext *avctx)

 #ifdef CONFIG_ENCODERS

 #ifdef CONFIG_RISKY

+    if (s->out_format == FMT_H261)

+        ff_h261_encode_init(s);

     if (s->out_format == FMT_H263)

         h263_encode_init(s);

     if(s->msmpeg4_version)

@@ -1215,7 +1222,7 @@ int MPV_encode_init(AVCodecContext *avctx)

         if(s->codec_id==CODEC_ID_MPEG4 && s->mpeg_quant){

             s->intra_matrix[j] = ff_mpeg4_default_intra_matrix[i];

             s->inter_matrix[j] = ff_mpeg4_default_non_intra_matrix[i];

-        }else if(s->out_format == FMT_H263){

+        }else if(s->out_format == FMT_H263 || s->out_format == FMT_H261){

             s->intra_matrix[j] =

             s->inter_matrix[j] = ff_mpeg1_default_non_intra_matrix[i];

         }else

@@ -4127,6 +4134,8 @@ static void encode_mb(MpegEncContext *s, int motion_x, int motion_y)

         msmpeg4_encode_mb(s, s->block, motion_x, motion_y); break;

     case CODEC_ID_WMV2:

          ff_wmv2_encode_mb(s, s->block, motion_x, motion_y); break;

+    case CODEC_ID_H261:

+        ff_h261_encode_mb(s, s->block, motion_x, motion_y); break;

     case CODEC_ID_H263:

     case CODEC_ID_H263P:

     case CODEC_ID_FLV1:

@@ -4495,15 +4504,21 @@ static int encode_thread(AVCodecContext *c, void *arg){

         ff_init_block_index(s);

         for(mb_x=0; mb_x < s->mb_width; mb_x++) {

-            const int xy= mb_y*s->mb_stride + mb_x;

+            int xy= mb_y*s->mb_stride + mb_x; // removed const, H261 needs to adjust this

             int mb_type= s->mb_type[xy];

 //            int d;

             int dmin= INT_MAX;

             int dir;

             s->mb_x = mb_x;

+            s->mb_y = mb_y;  // moved into loop, can get changed by H.261

             ff_update_block_index(s);

+            if(s->codec_id == CODEC_ID_H261){

+                ff_h261_reorder_mb_index(s);

+                xy= s->mb_y*s->mb_stride + s->mb_x;

+            }

+

             /* write gob / video packet header  */

 #ifdef CONFIG_RISKY

             if(s->rtp_mode){

@@ -5215,6 +5230,9 @@ static void encode_picture(MpegEncContext *s, int picture_number)

         mjpeg_picture_header(s);

         break;

 #ifdef CONFIG_RISKY

+    case FMT_H261:

+        ff_h261_encode_picture_header(s, picture_number);

+        break;

     case FMT_H263:

         if (s->codec_id == CODEC_ID_WMV2) 

             ff_wmv2_encode_picture_header(s, picture_number);

@@ -865,6 +865,12 @@ extern const uint8_t ff_h263_loop_filter_strength[32];

 /* h261.c */

 void ff_h261_loop_filter(MpegEncContext *s);

+void ff_h261_reorder_mb_index(MpegEncContext* s);

+void ff_h261_encode_mb(MpegEncContext *s,

+                    DCTELEM block[6][64],

+                    int motion_x, int motion_y);

+void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number);

+void ff_h261_encode_init(MpegEncContext *s);

 /* h263.c, h263dec.c */

@@ -344,6 +344,21 @@ AVInputFormat h261_iformat = {

     .value = CODEC_ID_H261,

 };

+#ifdef CONFIG_ENCODERS

+AVOutputFormat h261_oformat = {

+    "h261",

+    "raw h261",

+    "video/x-h261",

+    "h261",

+    0,

+    0,

+    CODEC_ID_H261,

+    raw_write_header,

+    raw_write_packet,

+    raw_write_trailer,

+};

+#endif //CONFIG_ENCODERS

+

 AVInputFormat h263_iformat = {

     "h263",

     "raw h263",

@@ -648,6 +663,7 @@ int raw_init(void)

     av_register_input_format(&dts_iformat);

     av_register_input_format(&h261_iformat);

+    av_register_output_format(&h261_oformat);

     av_register_input_format(&h263_iformat);

     av_register_output_format(&h263_oformat);