[FFmpeg-devel] avcodec: add MagicYUV encoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>
---
 libavcodec/Makefile      |   1 +
 libavcodec/allcodecs.c   |   2 +-
 libavcodec/magicyuvenc.c | 482 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 484 insertions(+), 1 deletion(-)
 create mode 100644 libavcodec/magicyuvenc.c

On 14.07.2017, at 16:30, Paul B Mahol <onemda@gmail.com> wrote:

> Signed-off-by: Paul B Mahol <onemda@gmail.com>


Probably not making myself popular with that request, but maybe you
could do a pass over the code and add comments for things that might
be useful for people to know?
If you need concrete examples I am thinking of qsort vs AV_QSORT usage, and comments sumarizing what some of those loops with large bodies do, but there might be other things valuable to dump brain -> code.

Thanks,
Reimar

On 7/14/2017 11:30 AM, Paul B Mahol wrote:
> Signed-off-by: Paul B Mahol <onemda@gmail.com>
> ---
>  libavcodec/Makefile      |   1 +
>  libavcodec/allcodecs.c   |   2 +-
>  libavcodec/magicyuvenc.c | 482 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 484 insertions(+), 1 deletion(-)
>  create mode 100644 libavcodec/magicyuvenc.c
> 
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 59029a8..af7e1f2 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -384,6 +384,7 @@ OBJS-$(CONFIG_M101_DECODER)            += m101.o
>  OBJS-$(CONFIG_MACE3_DECODER)           += mace.o
>  OBJS-$(CONFIG_MACE6_DECODER)           += mace.o
>  OBJS-$(CONFIG_MAGICYUV_DECODER)        += magicyuv.o
> +OBJS-$(CONFIG_MAGICYUV_ENCODER)        += magicyuvenc.o
>  OBJS-$(CONFIG_MDEC_DECODER)            += mdec.o mpeg12.o mpeg12data.o
>  OBJS-$(CONFIG_METASOUND_DECODER)       += metasound.o metasound_data.o \
>                                            twinvq.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index 0243f47..2fe415a 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -239,7 +239,7 @@ static void register_all(void)
>      REGISTER_ENCODER(LJPEG,             ljpeg);
>      REGISTER_DECODER(LOCO,              loco);
>      REGISTER_DECODER(M101,              m101);
> -    REGISTER_DECODER(MAGICYUV,          magicyuv);
> +    REGISTER_ENCDEC (MAGICYUV,          magicyuv);
>      REGISTER_DECODER(MDEC,              mdec);
>      REGISTER_DECODER(MIMIC,             mimic);
>      REGISTER_ENCDEC (MJPEG,             mjpeg);
> diff --git a/libavcodec/magicyuvenc.c b/libavcodec/magicyuvenc.c
> new file mode 100644
> index 0000000..bf79247
> --- /dev/null
> +++ b/libavcodec/magicyuvenc.c
> @@ -0,0 +1,482 @@
> +/*
> + * MagicYUV encoder
> + * Copyright (c) 2017 Paul B Mahol
> + *
> + * 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 <stdlib.h>
> +#include <string.h>
> +
> +#include "libavutil/pixdesc.h"
> +#include "libavutil/qsort.h"
> +
> +#include "avcodec.h"
> +#include "bytestream.h"
> +#include "put_bits.h"
> +#include "internal.h"
> +#include "thread.h"
> +#include "lossless_videoencdsp.h"
> +
> +typedef enum Prediction {
> +    LEFT = 1,
> +    GRADIENT,
> +    MEDIAN,
> +} Prediction;
> +
> +typedef struct HuffEntry {
> +    uint8_t  sym;
> +    uint8_t  len;
> +    uint32_t code;
> +} HuffEntry;
> +
> +typedef struct MagicYUVContext {
> +    PutBitContext        pb;
> +    int                  planes;
> +    uint8_t              format;
> +    AVFrame             *p;
> +    int                  max;
> +    int                  slice_height;
> +    int                  nb_slices;
> +    int                  correlate;
> +    int                  hshift[4];
> +    int                  vshift[4];
> +    uint8_t             *slices[4];
> +    unsigned             slice_pos[4];
> +    unsigned             tables_size;
> +    HuffEntry            he[4][256];
> +    LLVidEncDSPContext   llvidencdsp;

Missing configure dependency for this.

> +} MagicYUVContext;
> +
> +static av_cold int magy_encode_init(AVCodecContext *avctx)
> +{
> +    MagicYUVContext *s = avctx->priv_data;
> +    int i;
> +
> +    switch (avctx->pix_fmt) {
> +    case AV_PIX_FMT_GBRP:
> +        avctx->codec_tag = MKTAG('M', '8', 'R', 'G');
> +        s->correlate = 1;
> +        s->format = 0x65;
> +        break;
> +    case AV_PIX_FMT_GBRAP:
> +        avctx->codec_tag = MKTAG('M', '8', 'R', 'A');
> +        s->correlate = 1;
> +        s->format = 0x66;
> +        break;
> +    case AV_PIX_FMT_YUV420P:
> +        avctx->codec_tag = MKTAG('M', '8', 'Y', '0');
> +        s->hshift[1] =
> +        s->vshift[1] =
> +        s->hshift[2] =
> +        s->vshift[2] = 1;
> +        s->format = 0x69;
> +        break;
> +    case AV_PIX_FMT_YUV422P:
> +        avctx->codec_tag = MKTAG('M', '8', 'Y', '2');
> +        s->hshift[1] =
> +        s->hshift[2] = 1;
> +        s->format = 0x68;
> +        break;
> +    case AV_PIX_FMT_YUV444P:
> +        avctx->codec_tag = MKTAG('M', '8', 'Y', '4');
> +        s->format = 0x67;
> +        break;
> +    case AV_PIX_FMT_YUVA444P:
> +        avctx->codec_tag = MKTAG('M', '8', 'Y', 'A');
> +        s->format = 0x6a;
> +        break;
> +    case AV_PIX_FMT_GRAY8:
> +        avctx->codec_tag = MKTAG('M', '8', 'G', '0');
> +        s->format = 0x6b;
> +        break;
> +    default:
> +        av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format: %d\n",
> +               avctx->pix_fmt);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    ff_llvidencdsp_init(&s->llvidencdsp);
> +
> +    s->planes = av_pix_fmt_count_planes(avctx->pix_fmt);
> +
> +    s->nb_slices = 1;
> +
> +    for (i = 0; i < s->planes; i++) {
> +        s->slices[i] = av_malloc(avctx->width * (avctx->height + 2) +
> +                                 AV_INPUT_BUFFER_PADDING_SIZE);
> +        if (!s->slices[i]) {
> +            av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer.\n");
> +            return AVERROR(ENOMEM);
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static void left_predict(uint8_t *src, uint8_t *dst, ptrdiff_t stride,
> +                         int width, int height)
> +{
> +    uint8_t prev = 0;
> +    int i, j;
> +
> +    for (i = 0; i < width; i++) {
> +        dst[i] = src[i] - prev;
> +        prev   = src[i];
> +    }
> +    dst += width;
> +    src += stride;
> +    for (j = 1; j < height; j++) {
> +        prev = src[-stride];
> +        for (i = 0; i < width; i++) {
> +            dst[i] = src[i] - prev;
> +            prev   = src[i];
> +        }
> +        dst += width;
> +        src += stride;
> +    }
> +}
> +
> +static int ff_magy_huff_cmp_len(const void *a, const void *b)

static functions don't use the ff_ prefix.

> +{
> +    const HuffEntry *aa = a, *bb = b;
> +    return (aa->len - bb->len)*256 + aa->sym - bb->sym;
> +}
> +
> +static int huff_cmp_sym(const void *a, const void *b)
> +{
> +    const HuffEntry *aa = a, *bb = b;
> +    return bb->sym - aa->sym;
> +}
> +
> +static void calculate_codes(HuffEntry *he)
> +{
> +    uint32_t code;
> +    int i;
> +
> +    qsort(he, 256, sizeof(*he), ff_magy_huff_cmp_len);
> +
> +    code = 1;
> +    for (i = 255; i >= 0; i--) {
> +        he[i].code  = code >> (32 - he[i].len);
> +        code       += 0x80000000u >> (he[i].len - 1);
> +    }
> +
> +    qsort(he, 256, sizeof(*he), huff_cmp_sym);
> +}
> +
> +typedef struct PTable {
> +    int     value;  ///< input value
> +    int64_t prob;   ///< number of occurences of this value in input
> +} PTable;

Put all the struct definitions at the beginning of the file.

> +
> +static void count_usage(uint8_t *src, int width,
> +                        int height, PTable *counts)
> +{
> +    int i, j;
> +
> +    for (j = 0; j < height; j++) {
> +        for (i = 0; i < width; i++) {
> +            counts[src[i]].prob++;
> +        }
> +        src += width;
> +    }
> +}
> +
> +typedef struct PackageMergerList {
> +    int nitems;             ///< number of items in the list and probability      ex. 4
> +    int item_idx[515];      ///< index range for each item in items                   0, 2, 5, 9, 13
> +    int probability[514];   ///< probability of each item                             3, 8, 18, 46
> +    int items[257 * 16];    ///< chain of all individual values that make up items    A, B, A, B, C, A, B, C, D, C, D, D, E
> +} PackageMergerList;
> +
> +static int compare_by_prob(const void *a, const void *b)
> +{
> +    PTable a_val = *(PTable *)a;
> +    PTable b_val = *(PTable *)b;
> +    return a_val.prob - b_val.prob;
> +}
> +
> +static void ff_magy_huffman_compute_bits(PTable *prob_table, HuffEntry *distincts,
> +                                         int size, int max_length)
> +{
> +    PackageMergerList list_a, list_b, *to = &list_a, *from = &list_b, *temp;
> +    int times, i, j, k;
> +    int nbits[257] = {0};
> +    int min;
> +
> +    av_assert0(max_length > 0);
> +
> +    to->nitems = 0;
> +    from->nitems = 0;
> +    to->item_idx[0] = 0;
> +    from->item_idx[0] = 0;
> +    AV_QSORT(prob_table, size, PTable, compare_by_prob);
> +
> +    for (times = 0; times <= max_length; times++) {
> +        to->nitems = 0;
> +        to->item_idx[0] = 0;
> +
> +        j = 0;
> +        k = 0;
> +
> +        if (times < max_length) {
> +            i = 0;
> +        }
> +        while (i < size || j + 1 < from->nitems) {
> +            to->nitems++;
> +            to->item_idx[to->nitems] = to->item_idx[to->nitems - 1];
> +            if (i < size &&
> +                (j + 1 >= from->nitems ||
> +                 prob_table[i].prob <
> +                     from->probability[j] + from->probability[j + 1])) {
> +                to->items[to->item_idx[to->nitems]++] = prob_table[i].value;
> +                to->probability[to->nitems - 1] = prob_table[i].prob;
> +                i++;
> +            } else {
> +                for (k = from->item_idx[j]; k < from->item_idx[j + 2]; k++) {
> +                    to->items[to->item_idx[to->nitems]++] = from->items[k];
> +                }
> +                to->probability[to->nitems - 1] =
> +                    from->probability[j] + from->probability[j + 1];
> +                j += 2;
> +            }
> +        }
> +        temp = to;
> +        to = from;
> +        from = temp;
> +    }
> +
> +    min = (size - 1 < from->nitems) ? size - 1 : from->nitems;
> +    for (i = 0; i < from->item_idx[min]; i++) {
> +        nbits[from->items[i]]++;
> +    }
> +
> +    for (i = 0; i < size; i++) {
> +        distincts[i].sym = i;
> +        distincts[i].len = nbits[i];
> +    }
> +}
> +
> +static int encode_table(AVCodecContext *avctx, uint8_t *dst,
> +                        int width, int height,
> +                        PutBitContext *pb, HuffEntry *he)
> +{
> +    PTable counts[257] = { 0 };
> +    int i;
> +
> +    count_usage(dst, width, height, counts);
> +
> +    for (i = 0; i < 256; i++) {
> +        counts[i].prob++;
> +        counts[i].value = i;
> +    }
> +    counts[i].value = 256;
> +    counts[i].prob  = 0;
> +
> +    ff_magy_huffman_compute_bits(counts, he, 256, 16);
> +
> +    calculate_codes(he);
> +
> +    for (i = 0; i < 256;) {
> +        put_bits(pb, 1, 0);
> +        put_bits(pb, 7, he[i].len);
> +        i += 1;

?

> +    }
> +
> +    return 0;
> +}
> +
> +static int encode_slice(uint8_t *src, uint8_t *dst, int dst_size,
> +                        int width, int height, HuffEntry *he)
> +{
> +    PutBitContext pb;
> +    int i, j;
> +    int count;
> +
> +    init_put_bits(&pb, dst, dst_size);
> +
> +    put_bits(&pb, 8, 0);
> +    put_bits(&pb, 8, LEFT);
> +
> +    for (j = 0; j < height; j++) {
> +        for (i = 0; i < width; i++) {
> +            const int idx = src[i];
> +            put_bits(&pb, he[idx].len, he[idx].code);
> +        }
> +
> +        src += width;
> +    }
> +
> +    count = put_bits_count(&pb) & 0x1F;
> +
> +    if (count)
> +        put_bits(&pb, 32 - count, 0);
> +
> +    count = put_bits_count(&pb);
> +
> +    flush_put_bits(&pb);
> +
> +    return count >> 3;
> +}
> +
> +static int magy_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
> +                             const AVFrame *frame, int *got_packet)
> +{
> +    MagicYUVContext *s = avctx->priv_data;
> +    PutByteContext pb;
> +    const int width = avctx->width, height = avctx->height;
> +    int pos, slice, i, j, ret = 0;
> +
> +    ret = ff_alloc_packet2(avctx, pkt, (256 + 4 * s->nb_slices + width * height) *
> +                           s->planes + 256, 0);
> +    if (ret < 0)
> +        return ret;
> +
> +    bytestream2_init_writer(&pb, pkt->data, pkt->size);
> +    bytestream2_put_le32(&pb, MKTAG('M', 'A', 'G', 'Y'));
> +    bytestream2_put_le32(&pb, 32);
> +    bytestream2_put_byte(&pb, 7);
> +    bytestream2_put_byte(&pb, s->format);
> +    bytestream2_put_byte(&pb, 0);
> +    bytestream2_put_byte(&pb, 0);
> +    bytestream2_put_le32(&pb, 0);
> +
> +    bytestream2_put_le32(&pb, avctx->width);
> +    bytestream2_put_le32(&pb, avctx->height);
> +    bytestream2_put_le32(&pb, avctx->width);
> +    bytestream2_put_le32(&pb, avctx->height);
> +    bytestream2_put_le32(&pb, 0);
> +
> +    for (i = 0; i < s->planes; i++) {
> +        bytestream2_put_le32(&pb, 0);
> +        for (j = 1; j < s->nb_slices; j++) {
> +            bytestream2_put_le32(&pb, 0);
> +        }
> +    }
> +
> +    bytestream2_put_byte(&pb, s->planes);
> +
> +    for (i = 0; i < s->planes; i++) {
> +        for (slice = 0; slice < s->nb_slices; slice++) {
> +            bytestream2_put_byte(&pb, i);
> +        }
> +    }
> +
> +    if (s->correlate) {
> +        uint8_t *r, *g, *b;
> +        AVFrame *p = av_frame_clone(frame);
> +
> +        g = p->data[0];
> +        b = p->data[1];
> +        r = p->data[2];
> +
> +        for (i = 0; i < height; i++) {
> +            s->llvidencdsp.diff_bytes(b, b, g, width);
> +            s->llvidencdsp.diff_bytes(r, r, g, width);
> +            g += p->linesize[0];
> +            b += p->linesize[1];
> +            r += p->linesize[2];
> +        }
> +
> +        FFSWAP(uint8_t*, p->data[0], p->data[1]);
> +        FFSWAP(int, p->linesize[0], p->linesize[1]);
> +
> +        for (i = 0; i < s->planes; i++) {
> +            for (slice = 0; slice < s->nb_slices; slice++) {
> +                left_predict(p->data[i], s->slices[i], p->linesize[i],
> +                             p->width, p->height);
> +            }
> +        }
> +
> +        av_frame_free(&p);
> +    } else {
> +        for (i = 0; i < s->planes; i++) {
> +            for (slice = 0; slice < s->nb_slices; slice++) {
> +                left_predict(frame->data[i], s->slices[i], frame->linesize[i],
> +                             AV_CEIL_RSHIFT(frame->width, s->hshift[i]),
> +                             AV_CEIL_RSHIFT(frame->height, s->vshift[i]));
> +            }
> +        }
> +    }
> +
> +    init_put_bits(&s->pb, pkt->data + bytestream2_tell_p(&pb), bytestream2_get_bytes_left_p(&pb));
> +
> +    for (i = 0; i < s->planes; i++) {
> +        encode_table(avctx, s->slices[i],
> +                     AV_CEIL_RSHIFT(frame->width,  s->hshift[i]),
> +                     AV_CEIL_RSHIFT(frame->height, s->vshift[i]),
> +                     &s->pb, s->he[i]);
> +    }
> +    s->tables_size = (put_bits_count(&s->pb) + 7) >> 3;
> +    bytestream2_skip_p(&pb, s->tables_size);
> +
> +    for (i = 0; i < s->planes; i++) {
> +        unsigned slice_size;
> +
> +        s->slice_pos[i] = bytestream2_tell_p(&pb);
> +        slice_size = encode_slice(s->slices[i], pkt->data + bytestream2_tell_p(&pb),
> +                                  bytestream2_get_bytes_left_p(&pb),
> +                                  AV_CEIL_RSHIFT(frame->width,  s->hshift[i]),
> +                                  AV_CEIL_RSHIFT(frame->height, s->vshift[i]),
> +                                  s->he[i]);
> +        bytestream2_skip_p(&pb, slice_size);
> +    }
> +
> +    pos = bytestream2_tell_p(&pb);
> +    bytestream2_seek_p(&pb, 32, SEEK_SET);
> +    bytestream2_put_le32(&pb, s->slice_pos[0] - 32);
> +    for (i = 0; i < s->planes; i++) {
> +        bytestream2_put_le32(&pb, s->slice_pos[i] - 32);
> +    }
> +    bytestream2_seek_p(&pb, pos, SEEK_SET);
> +
> +    pkt->size   = bytestream2_tell_p(&pb);
> +    pkt->flags |= AV_PKT_FLAG_KEY;
> +
> +    *got_packet = 1;
> +
> +    return 0;
> +}
> +
> +static av_cold int magy_encode_close(AVCodecContext *avctx)
> +{
> +    MagicYUVContext *s = avctx->priv_data;
> +    int i;
> +
> +    for (i = 0; i < s->planes; i++)
> +        av_freep(&s->slices[i]);
> +
> +    return 0;
> +}
> +
> +AVCodec ff_magicyuv_encoder = {
> +    .name             = "magicyuv",
> +    .long_name        = NULL_IF_CONFIG_SMALL("MagicYUV video"),
> +    .type             = AVMEDIA_TYPE_VIDEO,
> +    .id               = AV_CODEC_ID_MAGICYUV,
> +    .priv_data_size   = sizeof(MagicYUVContext),
> +    .init             = magy_encode_init,
> +    .close            = magy_encode_close,
> +    .encode2          = magy_encode_frame,
> +    .capabilities     = AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_INTRA_ONLY,
> +    .pix_fmts         = (const enum AVPixelFormat[]) {
> +                          AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_YUV422P,
> +                          AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVA444P, AV_PIX_FMT_GRAY8,
> +                          AV_PIX_FMT_NONE
> +                      },
> +};
>