Am Mi., 24. Juni 2020 um 20:55 Uhr schrieb <gautamr...@gmail.com>:
>
> From: Gautam Ramakrishnan <gautamr...@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 | 176 +++++++++++++++++++++++++++++++++++++++
> libavformat/allformats.c | 1 +
> libavformat/img2dec.c | 11 +++
> 7 files changed, 229 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,
You cannot put this in the middle of an enum, it breaks abi.
> 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
Apart from this:
Why is the header file needed at all?
> diff --git a/libavcodec/pgxdec.c b/libavcodec/pgxdec.c
> new file mode 100644
> index 0000000000..233bf34717
> --- /dev/null
> +++ b/libavcodec/pgxdec.c
> @@ -0,0 +1,176 @@
> +/*
> + * 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;
> + }
Is this needed, are other decoders testing this?
> +
> + for (i = 0; i < 6; i++) {
> + if (header_start[i] != (char)bytestream2_get_byteu(&s->g)) {
> + return AVERROR_INVALIDDATA;
> + }
Use memcmp() or consider to drop this check:
If a user forces this decoder, it should not be necessary to depend on this.
> + }
> + 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)
> +{
> + 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;
PGXContext *s = ...
> + 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;
> +
> + 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
Please fix this.
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
I believe other developers will request that you split the demuxer
and the decoder patch.
> 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;
if (AV_RB24(b) != ...)
return 0;
> + ret = ret && av_match_ext(p->filename, "pgx");
> + if (ret)
> + return AVPROBE_SCORE_EXTENSION + 1;
You should instead check if the file internally looks like pgx,
checking the extension is a final possibility for things that
are impossible to detect (which I think is not the case here).
Carl Eugen
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