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avcodec/dvenc: Support adjusting the quantizer deadzone 

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-08-07 01:20:55 +02:00
parent a5380f9c1c
commit fea7bc9e7b
2 changed files with 26 additions and 1 deletions
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3
libavcodec/dv.h
View File

@ -38,6 +38,7 @@ typedef struct DVwork_chunk {
} DVwork_chunk;
typedef struct DVVideoContext {
AVClass *avclass;
const AVDVProfile *sys;
const AVFrame *frame;
AVCodecContext *avctx;
@ -51,6 +52,8 @@ typedef struct DVVideoContext {
me_cmp_func ildct_cmp;
DVwork_chunk work_chunks[4 * 12 * 27];
uint32_t idct_factor[2 * 4 * 16 * 64];
int quant_deadzone;
} DVVideoContext;
enum dv_section_type {

24
libavcodec/dvenc.c
View File

@ -17,6 +17,8 @@
* 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
*
* quant_deadzone code and fixes sponsored by NOA GmbH
*/
/**
@ -28,6 +30,7 @@
#include "libavutil/attributes.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avcodec.h"
@ -265,6 +268,8 @@ static av_always_inline int dv_init_enc_block(EncBlockInfo *bi, uint8_t *data,
#endif
int max = classes[0];
int prev = 0;
const unsigned deadzone = s->quant_deadzone;
const unsigned threshold = 2 * deadzone;
av_assert2((((int) blk) & 15) == 0);
@ -297,13 +302,15 @@ static av_always_inline int dv_init_enc_block(EncBlockInfo *bi, uint8_t *data,
for (i = mb_area_start[area]; i < mb_area_start[area + 1]; i++) {
int level = blk[zigzag_scan[i]];
if (level + 15 > 30U) {
if (level + deadzone > threshold) {
bi->sign[i] = (level >> 31) & 1;
/* Weight it and shift down into range, adding for rounding.
* The extra division by a factor of 2^4 reverses the 8x
* expansion of the DCT AND the 2x doubling of the weights. */
level = (FFABS(level) * weight[i] + (1 << (dv_weight_bits + 3))) >>
(dv_weight_bits + 4);
if (!level)
continue;
bi->mb[i] = level;
if (level > max)
max = level;
@ -746,6 +753,20 @@ FF_ENABLE_DEPRECATION_WARNINGS
return 0;
}
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
#define OFFSET(x) offsetof(DVVideoContext, x)
static const AVOption dv_options[] = {
{ "quant_deadzone", "Quantizer dead zone", OFFSET(quant_deadzone), AV_OPT_TYPE_INT, { .i64 = 15 }, 0, 1024, VE },
{ NULL },
};
static const AVClass dvvideo_encode_class = {
.class_name = "dvvideo encoder",
.item_name = av_default_item_name,
.option = dv_options,
.version = LIBAVUTIL_VERSION_INT,
};
AVCodec ff_dvvideo_encoder = {
.name = "dvvideo",
.long_name = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),
@ -759,4 +780,5 @@ AVCodec ff_dvvideo_encoder = {
AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV422P,
AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE
},
.priv_class = &dvvideo_encode_class,
};