On Thu, Mar 20, 2014 at 03:14:55AM +0100, Vittorio Giovara wrote:
> ---
> My first encoder/decoder \o/
>
> A sum up of the format is available here
> http://www.mediatel.lu/workshop/graphic/2D_fileformat/h_aliaspix.html
> GIMP is able to read and write PIX images, it's completely compatibile with
> the ones
> produced/read from this decoder/encoder.
>
> Cheers,
> Vittorio
>
> Changelog | 1 +
> doc/general.texi | 2 +
> libavcodec/Makefile | 2 +
> libavcodec/alias.c | 222
> ++++++++++++++++++++++++++++++++++++++++++++++++
> libavcodec/allcodecs.c | 1 +
> libavcodec/avcodec.h | 1 +
> libavcodec/codec_desc.c | 7 ++
> libavcodec/version.h | 4 +-
> libavformat/img2.c | 1 +
> libavformat/img2enc.c | 2 +-
> 10 files changed, 240 insertions(+), 3 deletions(-)
> create mode 100644 libavcodec/alias.c
>
> diff --git a/libavcodec/alias.c b/libavcodec/alias.c
> new file mode 100644
> index 0000000..2469c2c
> --- /dev/null
> +++ b/libavcodec/alias.c
> @@ -0,0 +1,222 @@
> +/*
> + * Alias PIX image
> + * Copyright (C) 2014 Vittorio Giovara <vittorio.giov...@gmail.com>
> + *
> + * This file is part of Libav.
> + *
> + * Libav 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.
> + *
> + * Libav 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 Libav; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
> USA
> + */
> +
> +#include "libavutil/intreadwrite.h"
> +
> +#include "avcodec.h"
> +#include "bytestream.h"
> +#include "internal.h"
> +
> +#define ALIAS_HEADER_SIZE 10
> +
> +static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
> + AVPacket *avpkt)
> +{
> + AVFrame *f = data;
> + GetByteContext g;
> + int width, height, ret, i;
> + int format;
> + uint8_t *out_buf;
> + uint8_t packet[4];
> + int y = 0;
> +
> + bytestream2_init(&g, avpkt->data, avpkt->size);
> +
> + if (bytestream2_get_bytes_left(&g) < ALIAS_HEADER_SIZE) {
> + av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n",
> avpkt->size);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + width = bytestream2_get_be16(&g);
> + height = bytestream2_get_be16(&g);
> + bytestream2_skip(&g, 4); // obsolete offset
sounds WTFy and it's hard to guess that's obsolete X,Y offset, not some
pointer in the file
> + format = bytestream2_get_be16(&g);
> +
> + if (format == 24)
> + avctx->pix_fmt = AV_PIX_FMT_BGR24;
> + else if (format == 8)
> + avctx->pix_fmt = AV_PIX_FMT_GRAY8;
> + else {
> + av_log(avctx, AV_LOG_ERROR, "invalid format\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + ret = ff_set_dimensions(avctx, width, height);
> + if (ret < 0)
> + return ret;
> +
> + ret = ff_get_buffer(avctx, f, 0);
> + if (ret < 0)
> + return ret;
> +
> + f->pict_type = AV_PICTURE_TYPE_I;
> + f->key_frame = 1;
> +
> + if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
> + while (bytestream2_get_bytes_left(&g) > 0) {
> + /* set buffer at the right position at every new line */
> + if (width == avctx->width) {
> + width = 0;
> + out_buf = f->data[0] + f->linesize[0] * y++;
> + }
> + /* read and copy data */
> + AV_WB32(packet, bytestream2_get_be32(&g));
> + for (i = 0; i < packet[0]; i++) {
> + *out_buf++ = packet[1];
> + *out_buf++ = packet[2];
> + *out_buf++ = packet[3];
> + }
WTF?
run = get_byte();
r = get_byte();
g = get_byte();
b = get_byte();
for (i=0;i < run; i++){
*out++ = r;
*out++ = g;
*out++ = b;
}
or so
> + width += i;
also no check for overruns (e.g. image width = 16, i = 256, bye bye buffer
boundary)
> + }
> + } else { // AV_PIX_FMT_GRAY8
> + while (bytestream2_get_bytes_left(&g) > 0) {
> + /* set buffer at the right position at every new line */
> + if (width == avctx->width) {
> + width = 0;
> + out_buf = f->data[0] + f->linesize[0] * y++;
> + }
> + /* read and copy data */
> + AV_WB16(packet, bytestream2_get_be16(&g));
> + for (i = 0; i < packet[0]; i++)
> + *out_buf++ = packet[1];
> + width += i;
ditto
> + }
> + }
> +
> + *got_frame = 1;
> + return avpkt->size;
> +}
> +
> +static av_cold int encode_init(AVCodecContext *avctx)
> +{
> + avctx->coded_frame = av_frame_alloc();
> + if (!avctx->coded_frame)
> + return AVERROR(ENOMEM);
> +
> + return 0;
> +}
> +
> +static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
> + const AVFrame *frame, int *got_packet)
> +{
> + int width, height, depth, i, j, length, ret;
> + uint8_t *in_buf, *buf = pkt->data;
> +
> + avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
> + avctx->coded_frame->key_frame = 1;
> +
> + width = avctx->width;
> + height = avctx->height;
> +
> + if (width > 65535 || height > 65536) {
> + av_log(avctx, AV_LOG_ERROR, "unsupported size %dx%d\n", width,
> height);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + switch (avctx->pix_fmt) {
> + case AV_PIX_FMT_GRAY8:
> + depth = 8;
> + break;
> + case AV_PIX_FMT_RGB24:
> + case AV_PIX_FMT_RGBA:
> + depth = 24;
> + break;
> + default:
> + return AVERROR_INVALIDDATA;
> + }
> +
> + length = ALIAS_HEADER_SIZE + 4 * width * height; // max possible
> + if ((ret = ff_alloc_packet(pkt, length)) < 0) {
> + av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size
> %d.\n", length);
> + return ret;
> + }
> +
> + /* Encode header. */
> + bytestream_put_be16(&buf, width);
> + bytestream_put_be16(&buf, height);
> + bytestream_put_be32(&buf, 0L); /* offset */
> + bytestream_put_be16(&buf, depth);
> +
> + for (j = 0; j < height; j++) {
> + int count = 0;
> + in_buf = frame->data[0] + frame->linesize[0] * j;
> + for (i = 0; i < width; i += count) {
> + int pixel;
> +
> + if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
> + pixel = in_buf[0];
> + while (count < 255 && count + i < width && pixel ==
> in_buf[0]) {
> + count++;
> + in_buf++;
> + }
> + } else {
> + // the mask removes alpha in RGBA case
> + pixel = AV_RN32(in_buf) & 0x00FFFFFF;
fishy
> + while (count < 255 && count + i < width &&
> + pixel == (AV_RN32(in_buf) & 0x00FFFFFF) ) {
> + count++;
> + in_buf += avctx->pix_fmt == AV_PIX_FMT_RGB24 ? 3 : 4;
> + }
> + }
> +
> + bytestream_put_be32(&buf, (count << depth) | pixel);
> + }
> + }
> +
> + /* Total length */
> + pkt->size = buf - pkt->data;
> + pkt->flags |= AV_PKT_FLAG_KEY;
> + *got_packet = 1;
> +
> + return 0;
> +}
> +
> +static av_cold int encode_close(AVCodecContext *avctx)
> +{
> + av_frame_free(&avctx->coded_frame);
> + return 0;
> +}
> +
> +#if CONFIG_ALIAS_PIX_DECODER
> +AVCodec ff_alias_pix_decoder = {
> + .name = "alias_pix",
> + .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
> + .type = AVMEDIA_TYPE_VIDEO,
> + .id = AV_CODEC_ID_ALIAS_PIX,
> + .decode = decode_frame,
> + .capabilities = CODEC_CAP_DR1,
> +};
> +#endif
> +
> +#if CONFIG_ALIAS_PIX_ENCODER
> +AVCodec ff_alias_pix_encoder = {
> + .name = "alias_pix",
> + .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
> + .type = AVMEDIA_TYPE_VIDEO,
> + .id = AV_CODEC_ID_ALIAS_PIX,
> + .init = encode_init,
> + .encode2 = encode_frame,
> + .close = encode_close,
> + .pix_fmts = (const enum AVPixelFormat[]) {
> + AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
> + },
> +};
> +#endif
the rest if up to Diego
_______________________________________________
libav-devel mailing list
libav-devel@libav.org
https://lists.libav.org/mailman/listinfo/libav-devel
