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authorPanagiotis Issaris <takis.issaris@uhasselt.be>2007-05-21 12:51:29 +0000
committerPanagiotis Issaris <takis.issaris@uhasselt.be>2007-05-21 12:51:29 +0000
commitd632239c9cc5d97397b283bb7a36f2d9e818e1bd (patch)
tree8725994dfd4bc1274d909bd3a55f6458d7cad4e7 /libavcodec/h261enc.c
parente21c53bd392f78021220cb11b81bff7c936b1b13 (diff)
downloadffmpeg-d632239c9cc5d97397b283bb7a36f2d9e818e1bd.tar.gz
Split the h261.c file into separate files for the encoder, decoder and common stuff.
Originally committed as revision 9090 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/h261enc.c')
-rw-r--r--libavcodec/h261enc.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/libavcodec/h261enc.c b/libavcodec/h261enc.c
new file mode 100644
index 0000000000..a92060a4bb
--- /dev/null
+++ b/libavcodec/h261enc.c
@@ -0,0 +1,334 @@
+/*
+ * H261 encoder
+ * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2004 Maarten Daniels
+ *
+ * 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 h261enc.c
+ * H.261 encoder.
+ */
+
+#include "dsputil.h"
+#include "avcodec.h"
+#include "mpegvideo.h"
+#include "h261data.h"
+#include "h261.h"
+
+extern uint8_t ff_h261_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3];
+
+static void h261_encode_block(H261Context * h, DCTELEM * block,
+ int n);
+
+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;
+}
+
+void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){
+ H261Context * h = (H261Context *) s;
+ int format, temp_ref;
+
+ 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)30000 * s->avctx->time_base.num /
+ (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp
+ 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){
+ int index= s->mb_x + s->mb_y*s->mb_width;
+
+ if(index % 33 == 0)
+ h261_encode_gob_header(s,0);
+
+ /* 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
+ s->mb_x = index % 11 ; index /= 11;
+ s->mb_y = index % 3 ; index /= 3;
+ s->mb_x+= 11*(index % 2); index /= 2;
+ s->mb_y+= 3*index;
+
+ ff_init_block_index(s);
+ ff_update_block_index(s);
+ }
+}
+
+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 > 15)
+ 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 mvd, mv_diff_x, mv_diff_y, i, cbp;
+ cbp = 63; // avoid warning
+ mvd = 0;
+
+ h->current_mba++;
+ h->mtype = 0;
+
+ if (!s->mb_intra){
+ /* compute cbp */
+ cbp= get_cbp(s, block);
+
+ /* mvd indicates if this block is motion compensated */
+ mvd = motion_x | motion_y;
+
+ 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++;
+
+ if(mvd || s->loop_filter)
+ h->mtype+=3;
+ if(s->loop_filter)
+ h->mtype+=3;
+ if(cbp || s->dquant)
+ h->mtype++;
+ assert(h->mtype > 1);
+ }
+
+ 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)){
+ assert(cbp>0);
+ 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, ff_h261_rl_table_store);
+ }
+
+ 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,2,block[0]>0 ? 2 : 3 );
+ 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);
+ assert(level <= 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
+ }
+}
+
+AVCodec h261_encoder = {
+ "h261",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_H261,
+ sizeof(H261Context),
+ MPV_encode_init,
+ MPV_encode_picture,
+ MPV_encode_end,
+ .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, -1},
+};
+