FFmpeg
aliaspixenc.c
Go to the documentation of this file.
1 /*
2  * Alias PIX image encoder
3  * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/intreadwrite.h"
23 
24 #include "avcodec.h"
25 #include "bytestream.h"
26 #include "codec_internal.h"
27 #include "encode.h"
28 
29 #define ALIAS_HEADER_SIZE 10
30 
32  const AVFrame *frame, int *got_packet)
33 {
34  int width, height, bits_pixel, length, ret;
35  uint8_t *buf;
36 
37  width = avctx->width;
38  height = avctx->height;
39 
40  if (width > 65535 || height > 65535 ||
41  width * height >= INT_MAX / 4 - ALIAS_HEADER_SIZE) {
42  av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n", width, height);
43  return AVERROR_INVALIDDATA;
44  }
45 
46  switch (avctx->pix_fmt) {
47  case AV_PIX_FMT_GRAY8:
48  bits_pixel = 8;
49  break;
50  case AV_PIX_FMT_BGR24:
51  bits_pixel = 24;
52  break;
53  default:
54  return AVERROR(EINVAL);
55  }
56 
57  length = ALIAS_HEADER_SIZE + 4 * width * height; // max possible
58  if ((ret = ff_alloc_packet(avctx, pkt, length)) < 0)
59  return ret;
60 
61  buf = pkt->data;
62 
63  /* Encode header. */
64  bytestream_put_be16(&buf, width);
65  bytestream_put_be16(&buf, height);
66  bytestream_put_be32(&buf, 0); /* X, Y offset */
67  bytestream_put_be16(&buf, bits_pixel);
68 
69  for (int j = 0, bytes_pixel = bits_pixel >> 3; j < height; j++) {
70  const uint8_t *in_buf = frame->data[0] + frame->linesize[0] * j;
71  const uint8_t *const line_end = in_buf + bytes_pixel * width;
72  while (in_buf < line_end) {
73  int count = 0;
74  int pixel;
75 
76  if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
77  pixel = *in_buf;
78  while (count < 255 && in_buf < line_end && pixel == *in_buf) {
79  count++;
80  in_buf++;
81  }
82  bytestream_put_byte(&buf, count);
83  bytestream_put_byte(&buf, pixel);
84  } else { /* AV_PIX_FMT_BGR24 */
85  pixel = AV_RB24(in_buf);
86  while (count < 255 && in_buf < line_end &&
87  pixel == AV_RB24(in_buf)) {
88  count++;
89  in_buf += 3;
90  }
91  bytestream_put_byte(&buf, count);
92  bytestream_put_be24(&buf, pixel);
93  }
94  }
95  }
96 
97  /* Total length */
98  av_shrink_packet(pkt, buf - pkt->data);
99  *got_packet = 1;
100 
101  return 0;
102 }
103 
105  .p.name = "alias_pix",
106  CODEC_LONG_NAME("Alias/Wavefront PIX image"),
107  .p.type = AVMEDIA_TYPE_VIDEO,
108  .p.id = AV_CODEC_ID_ALIAS_PIX,
111  .p.pix_fmts = (const enum AVPixelFormat[]) {
113  },
114 };
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:71
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
encode_frame
static int encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *frame, int *got_packet)
Definition: aliaspixenc.c:31
ff_alias_pix_encoder
const FFCodec ff_alias_pix_encoder
Definition: aliaspixenc.c:104
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacket::data
uint8_t * data
Definition: packet.h:522
encode.h
FFCodec
Definition: codec_internal.h:127
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:76
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
av_shrink_packet
void av_shrink_packet(AVPacket *pkt, int size)
Reduce packet size, correctly zeroing padding.
Definition: avpacket.c:113
ALIAS_HEADER_SIZE
#define ALIAS_HEADER_SIZE
Definition: aliaspixenc.c:29
FF_CODEC_ENCODE_CB
#define FF_CODEC_ENCODE_CB(func)
Definition: codec_internal.h:315
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
width
#define width
intreadwrite.h
AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE
#define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE
This encoder can reorder user opaque values from input AVFrames and return them with corresponding ou...
Definition: codec.h:159
AV_CODEC_ID_ALIAS_PIX
@ AV_CODEC_ID_ALIAS_PIX
Definition: codec_id.h:229
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
frame
static AVFrame * frame
Definition: demux_decode.c:54
pixel
uint8_t pixel
Definition: tiny_ssim.c:41
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:81
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
codec_internal.h
height
#define height
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
AVCodecContext::height
int height
Definition: avcodec.h:625
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:662
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVCodecContext
main external API structure.
Definition: avcodec.h:445
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:72
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:625
bytestream.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:385
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_RB24
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:97
ff_alloc_packet
int ff_alloc_packet(AVCodecContext *avctx, AVPacket *avpkt, int64_t size)
Check AVPacket size and allocate data.
Definition: encode.c:61