FFmpeg
gdv.c
Go to the documentation of this file.
1 /*
2  * Gremlin Digital Video demuxer
3  * Copyright (c) 2017 Paul B Mahol
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 "avformat.h"
25 #include "avio.h"
26 #include "demux.h"
27 #include "internal.h"
28 
29 typedef struct GDVContext {
31  int is_audio;
35  unsigned pal[256];
36 } GDVContext;
37 
38 static int gdv_read_probe(const AVProbeData *p)
39 {
40  if (AV_RL32(p->buf) == 0x29111994)
41  return AVPROBE_SCORE_MAX;
42 
43  return 0;
44 }
45 
46 static struct {
47  uint16_t id;
48  uint16_t width;
49  uint16_t height;
50 } FixedSize[] = {
51  { 0, 320, 200},
52  { 1, 640, 200},
53  { 2, 320, 167},
54  { 3, 320, 180},
55  { 4, 320, 400},
56  { 5, 320, 170},
57  { 6, 160, 85},
58  { 7, 160, 83},
59  { 8, 160, 90},
60  { 9, 280, 128},
61  {10, 320, 240},
62  {11, 320, 201},
63  {16, 640, 400},
64  {17, 640, 200},
65  {18, 640, 180},
66  {19, 640, 167},
67  {20, 640, 170},
68  {21, 320, 240}
69 };
70 
72 {
73  GDVContext *gdv = ctx->priv_data;
74  AVIOContext *pb = ctx->pb;
75  AVStream *vst, *ast;
76  unsigned fps, snd_flags, vid_depth, size_id;
77 
78  avio_skip(pb, 4);
79  size_id = avio_rl16(pb);
80 
81  vst = avformat_new_stream(ctx, 0);
82  if (!vst)
83  return AVERROR(ENOMEM);
84 
85  vst->start_time = 0;
86  vst->duration =
87  vst->nb_frames = avio_rl16(pb);
88 
89  fps = avio_rl16(pb);
90  if (!fps)
91  return AVERROR_INVALIDDATA;
92 
93  snd_flags = avio_rl16(pb);
94  if (snd_flags & 1) {
95  ast = avformat_new_stream(ctx, 0);
96  if (!ast)
97  return AVERROR(ENOMEM);
98 
99  ast->start_time = 0;
101  ast->codecpar->codec_tag = 0;
102  ast->codecpar->sample_rate = avio_rl16(pb);
103  ast->codecpar->ch_layout.nb_channels = 1 + !!(snd_flags & 2);
104  if (snd_flags & 8) {
106  } else {
107  ast->codecpar->codec_id = (snd_flags & 4) ? AV_CODEC_ID_PCM_S16LE : AV_CODEC_ID_PCM_U8;
108  }
109 
110  avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);
111  gdv->audio_size = (ast->codecpar->sample_rate / fps) *
113  (1 + !!(snd_flags & 4)) / (1 + !!(snd_flags & 8));
114  gdv->is_audio = 1;
115  } else {
116  avio_skip(pb, 2);
117  }
118  vid_depth = avio_rl16(pb);
119  avio_skip(pb, 4);
120 
123  vst->codecpar->codec_tag = 0;
124  vst->codecpar->width = avio_rl16(pb);
125  vst->codecpar->height = avio_rl16(pb);
126 
127  if (vst->codecpar->width == 0 || vst->codecpar->height == 0) {
128  int i;
129 
130  for (i = 0; i < FF_ARRAY_ELEMS(FixedSize) - 1; i++) {
131  if (FixedSize[i].id == size_id)
132  break;
133  }
134 
135  vst->codecpar->width = FixedSize[i].width;
136  vst->codecpar->height = FixedSize[i].height;
137  }
138 
139  avpriv_set_pts_info(vst, 64, 1, fps);
140 
141  if (vid_depth & 1) {
142  int i;
143 
144  for (i = 0; i < 256; i++) {
145  unsigned r = avio_r8(pb);
146  unsigned g = avio_r8(pb);
147  unsigned b = avio_r8(pb);
148  gdv->pal[i] = 0xFFU << 24 | r << 18 | g << 10 | b << 2;
149  }
150  }
151 
152  gdv->is_first_video = 1;
153 
154  return 0;
155 }
156 
158 {
159  GDVContext *gdv = ctx->priv_data;
160  AVIOContext *pb = ctx->pb;
161  int ret;
162 
163  if (avio_feof(pb))
164  return pb->error ? pb->error : AVERROR_EOF;
165 
166  if (gdv->audio_size && gdv->is_audio) {
167  ret = av_get_packet(pb, pkt, gdv->audio_size);
168  if (ret < 0)
169  return ret;
170  pkt->stream_index = 1;
171  gdv->is_audio = 0;
172  } else {
173  uint8_t *pal;
174 
175  if (avio_rl16(pb) != 0x1305)
176  return AVERROR_INVALIDDATA;
177  ret = av_get_packet(pb, pkt, 4 + avio_rl16(pb));
178  if (ret < 0)
179  return ret;
180  pkt->stream_index = 0;
181  gdv->is_audio = 1;
182 
183  if (gdv->is_first_video) {
186  if (!pal) {
187  return AVERROR(ENOMEM);
188  }
189  memcpy(pal, gdv->pal, AVPALETTE_SIZE);
191  gdv->is_first_video = 0;
192  }
193  }
194 
195  return 0;
196 }
197 
199  .p.name = "gdv",
200  .p.long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
201  .priv_data_size = sizeof(GDVContext),
205 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:328
r
const char * r
Definition: vf_curves.c:127
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
b
#define b
Definition: input.c:41
AVIOContext::error
int error
contains the error code or 0 if no error happened
Definition: avio.h:239
AV_CODEC_ID_GDV
@ AV_CODEC_ID_GDV
Definition: codec_id.h:285
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:59
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:313
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:579
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:463
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:853
AV_PKT_DATA_PALETTE
@ AV_PKT_DATA_PALETTE
An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE bytes worth of palette.
Definition: packet.h:47
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:802
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:714
pkt
AVPacket * pkt
Definition: movenc.c:60
FF_ARRAY_ELEMS
#define FF_ARRAY_ELEMS(a)
Definition: sinewin_tablegen.c:29
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:42
gdv_read_probe
static int gdv_read_probe(const AVProbeData *p)
Definition: gdv.c:38
FixedSize
static struct @320 FixedSize[]
intreadwrite.h
id
uint16_t id
Definition: gdv.c:47
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
g
const char * g
Definition: vf_curves.c:128
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:134
GDVContext::audio_size
int audio_size
Definition: gdv.c:32
ctx
AVFormatContext * ctx
Definition: movenc.c:49
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:766
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
GDVContext::is_audio
int is_audio
Definition: gdv.c:31
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1297
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:180
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:184
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:804
GDVContext::audio_stream_index
int audio_stream_index
Definition: gdv.c:33
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
GDVContext::is_first_video
int is_first_video
Definition: gdv.c:30
avio.h
gdv_read_header
static int gdv_read_header(AVFormatContext *ctx)
Definition: gdv.c:71
GDVContext
Definition: gdv.c:30
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:41
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:603
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:530
height
uint16_t height
Definition: gdv.c:49
width
uint16_t width
Definition: gdv.c:48
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
AVCodecParameters::height
int height
Definition: codec_par.h:135
demux.h
ff_gdv_demuxer
const FFInputFormat ff_gdv_demuxer
Definition: gdv.c:198
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:104
GDVContext::pal
uint32_t pal[256]
Definition: gdv.c:37
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:743
avformat.h
GDVContext::video_stream_index
int video_stream_index
Definition: gdv.c:34
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
U
#define U(x)
Definition: vpx_arith.h:37
av_packet_new_side_data
uint8_t * av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type, size_t size)
Allocate new information of a packet.
Definition: packet.c:231
AVPacket::stream_index
int stream_index
Definition: packet.h:526
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:30
AV_CODEC_ID_PCM_U8
@ AV_CODEC_ID_PCM_U8
Definition: codec_id.h:333
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:501
FFInputFormat
Definition: demux.h:37
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:792
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1283
AV_CODEC_ID_GREMLIN_DPCM
@ AV_CODEC_ID_GREMLIN_DPCM
Definition: codec_id.h:434
gdv_read_packet
static int gdv_read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: gdv.c:157
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:346