[FFmpeg-devel] libavcodec/pgx: Added pgx decoder

From: Gautam Ramakrishnan <gautamramk@gmail.com>

This patch support to read and decode
pgx files.
---
 libavcodec/Makefile      |   1 +
 libavcodec/allcodecs.c   |   1 +
 libavcodec/codec_id.h    |   1 +
 libavcodec/pgx.h         |  38 +++++++++
 libavcodec/pgxdec.c      | 177 +++++++++++++++++++++++++++++++++++++++
 libavformat/allformats.c |   1 +
 libavformat/img2dec.c    |  11 +++
 7 files changed, 230 insertions(+)
 create mode 100644 libavcodec/pgx.h
 create mode 100644 libavcodec/pgxdec.c

On Wed, Jun 24, 2020 at 11:54 PM <gautamramk@gmail.com> wrote:
>
> From: Gautam Ramakrishnan <gautamramk@gmail.com>
>
> This patch support to read and decode
> pgx files.
> ---
>  libavcodec/Makefile      |   1 +
>  libavcodec/allcodecs.c   |   1 +
>  libavcodec/codec_id.h    |   1 +
>  libavcodec/pgx.h         |  38 +++++++++
>  libavcodec/pgxdec.c      | 177 +++++++++++++++++++++++++++++++++++++++
>  libavformat/allformats.c |   1 +
>  libavformat/img2dec.c    |  11 +++
>  7 files changed, 230 insertions(+)
>  create mode 100644 libavcodec/pgx.h
>  create mode 100644 libavcodec/pgxdec.c
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 5a6ea59715..0198c244e0 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -533,6 +533,7 @@ OBJS-$(CONFIG_PCX_ENCODER)             += pcxenc.o
>  OBJS-$(CONFIG_PFM_DECODER)             += pnmdec.o pnm.o
>  OBJS-$(CONFIG_PGM_DECODER)             += pnmdec.o pnm.o
>  OBJS-$(CONFIG_PGM_ENCODER)             += pnmenc.o
> +OBJS-$(CONFIG_PGX_DECODER)             += pgxdec.o
>  OBJS-$(CONFIG_PGMYUV_DECODER)          += pnmdec.o pnm.o
>  OBJS-$(CONFIG_PGMYUV_ENCODER)          += pnmenc.o
>  OBJS-$(CONFIG_PGSSUB_DECODER)          += pgssubdec.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index fa0c08d42e..b0217e6d6a 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -236,6 +236,7 @@ extern AVCodec ff_pcx_decoder;
>  extern AVCodec ff_pfm_decoder;
>  extern AVCodec ff_pgm_encoder;
>  extern AVCodec ff_pgm_decoder;
> +extern AVCodec ff_pgx_decoder;
>  extern AVCodec ff_pgmyuv_encoder;
>  extern AVCodec ff_pgmyuv_decoder;
>  extern AVCodec ff_pictor_decoder;
> diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
> index d885962c9c..027ef21c62 100644
> --- a/libavcodec/codec_id.h
> +++ b/libavcodec/codec_id.h
> @@ -111,6 +111,7 @@ enum AVCodecID {
>      AV_CODEC_ID_PPM,
>      AV_CODEC_ID_PBM,
>      AV_CODEC_ID_PGM,
> +    AV_CODEC_ID_PGX,
>      AV_CODEC_ID_PGMYUV,
>      AV_CODEC_ID_PAM,
>      AV_CODEC_ID_FFVHUFF,
> diff --git a/libavcodec/pgx.h b/libavcodec/pgx.h
> new file mode 100644
> index 0000000000..bbe93fafe7
> --- /dev/null
> +++ b/libavcodec/pgx.h
> @@ -0,0 +1,38 @@
> +/*
> + * PGX image format
> + * Copyright (c) 2020 Gautam Ramakrishnan
> + *
> + * 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
> + */
> +
> +#ifndef AVCODEC_PGX_H
> +#define AVCODEC_PGX_H
> +
> +#include "avcodec.h"
> +#include "bytestream.h"
> +
> +typedef struct PGXContext {
> +    GetByteContext  g;
> +    int depth;
> +    int sgnd;
> +    int width;
> +    int height;
> +} PGXContext;
> +
> +int ff_pgx_decode_header(AVCodecContext *avctx, PGXContext * const s);
> +
> +#endif /* AVCODEC_PNM_H */
> \ No newline at end of file
> diff --git a/libavcodec/pgxdec.c b/libavcodec/pgxdec.c
> new file mode 100644
> index 0000000000..f972853bf9
> --- /dev/null
> +++ b/libavcodec/pgxdec.c
> @@ -0,0 +1,177 @@
> +/*
> + * PGX image format
> + * Copyright (c) 2020 Gautam Ramakrishnan
> + *
> + * 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 "avcodec.h"
> +#include "internal.h"
> +#include "pgx.h"
> +
> +static int pgx_get_number(AVCodecContext *avctx, PGXContext * const s) {
> +    char number[10];
> +    int i;
> +    int ret;
> +    number[9] = '\0';
> +    for (i = 0; i < 9; i++) {
> +        if (!bytestream2_get_bytes_left(&s->g))
> +            return AVERROR_INVALIDDATA;
> +        number[i] = (char)bytestream2_get_byteu(&s->g);
> +        if (number[i] == ' ' || number[i] == 0xA || number[i] == 0xD) {
> +            number[i] = '\0';
> +            break;
> +        } else if (number[i] < '0' || number[i] > '9') {
> +            return AVERROR_INVALIDDATA;
> +        }
> +    }
> +    if (i > 9)
> +        return AVERROR_INVALIDDATA;
> +    ret = (int)strtol(number, NULL, 10);
> +    if (ret >= 0)
> +        return ret;
> +    return AVERROR_INVALIDDATA;
> +}
> +
> +int ff_pgx_decode_header(AVCodecContext *avctx, PGXContext * s)
> +{
> +    const char *header_start = "PG ML ";
> +    int i;
> +    int byte;
> +    if (bytestream2_get_bytes_left(&s->g) < 13) {
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    for (i = 0; i < 6; i++) {
> +        if (header_start[i] != (char)bytestream2_get_byteu(&s->g)) {
> +            return AVERROR_INVALIDDATA;
> +        }
> +    }
> +    byte = bytestream2_peek_byte(&s->g);
> +    if (byte == '+') {
> +        s->sgnd = 0;
> +        bytestream2_skip(&s->g, 1);
> +    } else if (byte == '-') {
> +        s->sgnd = 1;
> +        bytestream2_skip(&s->g, 1);
> +    }
> +
> +    if (bytestream2_peek_byte(&s->g) == ' ')
> +        bytestream2_skip(&s->g, 1);
> +    s->depth = pgx_get_number(avctx, s);
> +    s->width = pgx_get_number(avctx, s);
> +    s->height = pgx_get_number(avctx, s);
> +    if (bytestream2_peek_byte(&s->g) == 0xA)
> +        bytestream2_skip(&s->g, 1);
> +    return 0;
> +}
> +
> +static inline int write_frame_16(AVPacket *avpkt, AVFrame *frame, PGXContext * const s)
> +{
> +    printf("Something wrong here.\n");
> +    int i, j;
> +    for (i = 0; i < s->height; i++) {
> +        uint16_t* line = (uint16_t*)frame->data[0] + i*frame->linesize[0]/2;
> +        for (j = 0; j < s->width; j++) {
> +            int val;
> +            if (s->sgnd) {
> +                val = (int16_t)bytestream2_get_be16(&s->g) + (1 << (s->depth - 1));
> +                val <<= (16 - s->depth);
> +                *(line + j) = val;
> +            } else {
> +                val = bytestream2_get_be16u(&s->g);
> +                val <<= (16 - s->depth);
> +                *(line + j) = val;
> +            }
> +        }
> +        line += frame->linesize[0]/2;
> +    }
> +    return 0;
> +}
> +
> +static inline int write_frame_8(AVPacket *avpkt, AVFrame *frame, PGXContext * const s)
> +{
> +    int i, j;
> +    for (i = 0; i < s->height; i++) {
> +        uint8_t* line = frame->data[0] + i*frame->linesize[0];
> +        for (j = 0; j < s->width; j++) {
> +            int val;
> +            if (s->sgnd) {
> +                val = bytestream2_get_byte(&s->g) + (1 << (s->depth - 1));
> +                val <<= (8 - s->depth);
> +                *(line + j) = val;
> +            } else {
> +                val = bytestream2_get_byteu(&s->g);
> +                val <<= (8 - s->depth);
> +                *(line + j) = val;
> +            }
> +        }
> +        line += frame->linesize[0];
> +    }
> +    return 0;
> +}
> +
> +static int pgx_decode_frame(AVCodecContext *avctx, void *data,
> +                            int *got_frame, AVPacket *avpkt)
> +{
> +    PGXContext * s = avctx->priv_data;
> +    AVFrame * const p    = data;
> +    int ret;
> +    int num_vals;
> +    int bpp;
> +    bytestream2_init(&s->g, avpkt->data, avpkt->size);
> +    if ((ret = ff_pgx_decode_header(avctx, s)) < 0)
> +        return ret;
> +    av_log(avctx, AV_LOG_ERROR, "width = %d, height = %d signed = %d depth = %d.\n", s->width, s->height, s->sgnd, s->depth);
> +    num_vals = s->width * s->height;
> +
> +    if (ret = ff_set_dimensions(avctx, s->width, s->height) < 0)
> +        return ret;
> +
> +    if (s->depth <= 8) {
> +        avctx->pix_fmt = AV_PIX_FMT_GRAY8;
> +        bpp = 8;
> +    } else if (s->depth <= 16) {
> +        avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
> +        bpp = 16;
> +    } else {
> +        av_log(avctx, AV_LOG_ERROR, "Maximum depth of 16 bits supported.\n");
> +        return AVERROR_PATCHWELCOME;
> +    }
> +
> +    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
> +        return ret;
> +    *got_frame = 1;
> +    p->pict_type = AV_PICTURE_TYPE_I;
> +    p->key_frame = 1;
> +    avctx->bits_per_raw_sample = s->depth;
> +    if (bpp == 8)
> +        write_frame_8(avpkt, p, s);
> +    else if (bpp == 16)
> +        write_frame_16(avpkt, p, s);
> +    return 0;
> +}
> +
> +AVCodec ff_pgx_decoder = {
> +    .name           = "pgx",
> +    .long_name      = NULL_IF_CONFIG_SMALL("PGX image"),
> +    .type           = AVMEDIA_TYPE_VIDEO,
> +    .id             = AV_CODEC_ID_PGX,
> +    .priv_data_size = sizeof(PGXContext),
> +    .decode         = pgx_decode_frame,
> +    .capabilities   = AV_CODEC_CAP_DR1,
> +};
> \ No newline at end of file
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 97fd06debb..f8527b1fd4 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -488,6 +488,7 @@ extern AVInputFormat  ff_image_pbm_pipe_demuxer;
>  extern AVInputFormat  ff_image_pcx_pipe_demuxer;
>  extern AVInputFormat  ff_image_pgmyuv_pipe_demuxer;
>  extern AVInputFormat  ff_image_pgm_pipe_demuxer;
> +extern AVInputFormat  ff_image_pgx_pipe_demuxer;
>  extern AVInputFormat  ff_image_pictor_pipe_demuxer;
>  extern AVInputFormat  ff_image_png_pipe_demuxer;
>  extern AVInputFormat  ff_image_ppm_pipe_demuxer;
> diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c
> index ee7ceed08f..43270901ff 100644
> --- a/libavformat/img2dec.c
> +++ b/libavformat/img2dec.c
> @@ -1000,6 +1000,16 @@ static int pgmyuv_probe(const AVProbeData *p) // custom FFmpeg format recognized
>      return ret && av_match_ext(p->filename, "pgmyuv") ? ret : 0;
>  }
>
> +static int pgx_probe(const AVProbeData *p)
> +{
> +    const uint8_t *b = p->buf;
> +    int ret = (AV_RB32(b) & 0xFFFFFF00) == 0x50472000;
> +    ret = ret && av_match_ext(p->filename, "pgx");
> +    if (ret)
> +        return AVPROBE_SCORE_EXTENSION + 1;
> +    return 0;
> +}
> +
>  static int ppm_probe(const AVProbeData *p)
>  {
>      return pnm_magic_check(p, 3) || pnm_magic_check(p, 6) ? pnm_probe(p) : 0;
> @@ -1094,6 +1104,7 @@ IMAGEAUTO_DEMUXER(pbm,     AV_CODEC_ID_PBM)
>  IMAGEAUTO_DEMUXER(pcx,     AV_CODEC_ID_PCX)
>  IMAGEAUTO_DEMUXER(pgm,     AV_CODEC_ID_PGM)
>  IMAGEAUTO_DEMUXER(pgmyuv,  AV_CODEC_ID_PGMYUV)
> +IMAGEAUTO_DEMUXER(pgx,     AV_CODEC_ID_PGX)
>  IMAGEAUTO_DEMUXER(pictor,  AV_CODEC_ID_PICTOR)
>  IMAGEAUTO_DEMUXER(png,     AV_CODEC_ID_PNG)
>  IMAGEAUTO_DEMUXER(ppm,     AV_CODEC_ID_PPM)
> --
> 2.17.1
>

Please ignore this patch. Apologies