WebM Codec SDK: simple_encoder

WebM Codec SDK

simple_encoder
1/*
2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11// Simple Encoder
12// ==============
13//
14// This is an example of a simple encoder loop. It takes an input file in
15// YV12 format, passes it through the encoder, and writes the compressed
16// frames to disk in IVF format. Other decoder examples build upon this
17// one.
18//
19// The details of the IVF format have been elided from this example for
20// simplicity of presentation, as IVF files will not generally be used by
21// your application. In general, an IVF file consists of a file header,
22// followed by a variable number of frames. Each frame consists of a frame
23// header followed by a variable length payload. The length of the payload
24// is specified in the first four bytes of the frame header. The payload is
25// the raw compressed data.
26//
27// Standard Includes
28// -----------------
29// For encoders, you only have to include `vpx_encoder.h` and then any
30// header files for the specific codecs you use. In this case, we're using
31// vp8.
32//
33// Getting The Default Configuration
34// ---------------------------------
35// Encoders have the notion of "usage profiles." For example, an encoder
36// may want to publish default configurations for both a video
37// conferencing application and a best quality offline encoder. These
38// obviously have very different default settings. Consult the
39// documentation for your codec to see if it provides any default
40// configurations. All codecs provide a default configuration, number 0,
41// which is valid for material in the vacinity of QCIF/QVGA.
42//
43// Updating The Configuration
44// ---------------------------------
45// Almost all applications will want to update the default configuration
46// with settings specific to their usage. Here we set the width and height
47// of the video file to that specified on the command line. We also scale
48// the default bitrate based on the ratio between the default resolution
49// and the resolution specified on the command line.
50//
51// Initializing The Codec
52// ----------------------
53// The encoder is initialized by the following code.
54//
55// Encoding A Frame
56// ----------------
57// The frame is read as a continuous block (size width * height * 3 / 2)
58// from the input file. If a frame was read (the input file has not hit
59// EOF) then the frame is passed to the encoder. Otherwise, a NULL
60// is passed, indicating the End-Of-Stream condition to the encoder. The
61// `frame_cnt` is reused as the presentation time stamp (PTS) and each
62// frame is shown for one frame-time in duration. The flags parameter is
63// unused in this example. The deadline is set to VPX_DL_REALTIME to
64// make the example run as quickly as possible.
65
66// Forced Keyframes
67// ----------------
68// Keyframes can be forced by setting the VPX_EFLAG_FORCE_KF bit of the
69// flags passed to `vpx_codec_control()`. In this example, we force a
70// keyframe every <keyframe-interval> frames. Note, the output stream can
71// contain additional keyframes beyond those that have been forced using the
72// VPX_EFLAG_FORCE_KF flag because of automatic keyframe placement by the
73// encoder.
74//
75// Processing The Encoded Data
76// ---------------------------
77// Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data
78// for this frame. We write a IVF frame header, followed by the raw data.
79//
80// Cleanup
81// -------
82// The `vpx_codec_destroy` call frees any memory allocated by the codec.
83//
84// Error Handling
85// --------------
86// This example does not special case any error return codes. If there was
87// an error, a descriptive message is printed and the program exits. With
88// few exeptions, vpx_codec functions return an enumerated error status,
89// with the value `0` indicating success.
90//
91// Error Resiliency Features
92// -------------------------
93// Error resiliency is controlled by the g_error_resilient member of the
94// configuration structure. Use the `decode_with_drops` example to decode with
95// frames 5-10 dropped. Compare the output for a file encoded with this example
96// versus one encoded with the `simple_encoder` example.
97
98#include <stdio.h>
99#include <stdlib.h>
100#include <string.h>
101
102#include "vpx/vpx_encoder.h"
103
104#include "../tools_common.h"
105#include "../video_writer.h"
106
107static const char *exec_name;
108
109void usage_exit(void) {
110 fprintf(stderr,
111 "Usage: %s <codec> <width> <height> <infile> <outfile> "
112 "<keyframe-interval> <error-resilient> <frames to encode>\n"
113 "See comments in simple_encoder.c for more information.\n",
114 exec_name);
115 exit(EXIT_FAILURE);
116}
117
118static int encode_frame(vpx_codec_ctx_t *codec, vpx_image_t *img,
119 int frame_index, int flags, VpxVideoWriter *writer) {
120 int got_pkts = 0;
121 vpx_codec_iter_t iter = NULL;
122 const vpx_codec_cx_pkt_t *pkt = NULL;
123 const vpx_codec_err_t res =
124 vpx_codec_encode(codec, img, frame_index, 1, flags, VPX_DL_GOOD_QUALITY);
125 if (res != VPX_CODEC_OK) die_codec(codec, "Failed to encode frame");
126
127 while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) {
128 got_pkts = 1;
129
130 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
131 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
132 if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,
133 pkt->data.frame.sz,
134 pkt->data.frame.pts)) {
135 die_codec(codec, "Failed to write compressed frame");
136 }
137 printf(keyframe ? "K" : ".");
138 fflush(stdout);
139 }
140 }
141
142 return got_pkts;
143}
144
145// TODO(tomfinegan): Improve command line parsing and add args for bitrate/fps.
146int main(int argc, char **argv) {
147 FILE *infile = NULL;
148 vpx_codec_ctx_t codec;
149 vpx_codec_enc_cfg_t cfg;
150 int frame_count = 0;
151 vpx_image_t raw;
152 vpx_codec_err_t res;
153 VpxVideoInfo info = { 0, 0, 0, { 0, 0 } };
154 VpxVideoWriter *writer = NULL;
155 const VpxInterface *encoder = NULL;
156 const int fps = 30;
157 const int bitrate = 200;
158 int keyframe_interval = 0;
159 int max_frames = 0;
160 int frames_encoded = 0;
161 const char *codec_arg = NULL;
162 const char *width_arg = NULL;
163 const char *height_arg = NULL;
164 const char *infile_arg = NULL;
165 const char *outfile_arg = NULL;
166 const char *keyframe_interval_arg = NULL;
167
168 exec_name = argv[0];
169
170 if (argc != 9) die("Invalid number of arguments");
171
172 codec_arg = argv[1];
173 width_arg = argv[2];
174 height_arg = argv[3];
175 infile_arg = argv[4];
176 outfile_arg = argv[5];
177 keyframe_interval_arg = argv[6];
178 max_frames = (int)strtol(argv[8], NULL, 0);
179
180 encoder = get_vpx_encoder_by_name(codec_arg);
181 if (!encoder) die("Unsupported codec.");
182
183 info.codec_fourcc = encoder->fourcc;
184 info.frame_width = (int)strtol(width_arg, NULL, 0);
185 info.frame_height = (int)strtol(height_arg, NULL, 0);
186 info.time_base.numerator = 1;
187 info.time_base.denominator = fps;
188
189 if (info.frame_width <= 0 || info.frame_height <= 0 ||
190 (info.frame_width % 2) != 0 || (info.frame_height % 2) != 0) {
191 die("Invalid frame size: %dx%d", info.frame_width, info.frame_height);
192 }
193
194 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width,
195 info.frame_height, 1)) {
196 die("Failed to allocate image.");
197 }
198
199 keyframe_interval = (int)strtol(keyframe_interval_arg, NULL, 0);
200 if (keyframe_interval < 0) die("Invalid keyframe interval value.");
201
202 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
203
204 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
205 if (res)
206 die("Failed to get default codec config: %s", vpx_codec_err_to_string(res));
207
208 cfg.g_w = info.frame_width;
209 cfg.g_h = info.frame_height;
210 cfg.g_timebase.num = info.time_base.numerator;
211 cfg.g_timebase.den = info.time_base.denominator;
212 cfg.rc_target_bitrate = bitrate;
213 cfg.g_error_resilient = (vpx_codec_er_flags_t)strtoul(argv[7], NULL, 0);
214
215 writer = vpx_video_writer_open(outfile_arg, kContainerIVF, &info);
216 if (!writer) die("Failed to open %s for writing.", outfile_arg);
217
218 if (!(infile = fopen(infile_arg, "rb")))
219 die("Failed to open %s for reading.", infile_arg);
220
221 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0))
222 die("Failed to initialize encoder");
223
224 // Encode frames.
225 while (vpx_img_read(&raw, infile)) {
226 int flags = 0;
227 if (keyframe_interval > 0 && frame_count % keyframe_interval == 0)
228 flags |= VPX_EFLAG_FORCE_KF;
229 encode_frame(&codec, &raw, frame_count++, flags, writer);
230 frames_encoded++;
231 if (max_frames > 0 && frames_encoded >= max_frames) break;
232 }
233
234 // Flush encoder.
235 while (encode_frame(&codec, NULL, -1, 0, writer)) {
236 }
237
238 printf("\n");
239 fclose(infile);
240 printf("Processed %d frames.\n", frame_count);
241
242 vpx_img_free(&raw);
243 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
244
245 vpx_video_writer_close(writer);
246
247 return EXIT_SUCCESS;
248}
vpx_codec_err_to_string
const char * vpx_codec_err_to_string(vpx_codec_err_t err)
Convert error number to printable string.
vpx_codec_ctx_t
struct vpx_codec_ctx vpx_codec_ctx_t
Codec context structure.
vpx_codec_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.
vpx_codec_iter_t
const void * vpx_codec_iter_t
Iterator.
Definition vpx_codec.h:190
vpx_codec_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
vpx_codec_err_t
vpx_codec_err_t
Algorithm return codes.
Definition vpx_codec.h:93
VPX_CODEC_OK
@ VPX_CODEC_OK
Operation completed without error.
Definition vpx_codec.h:95
vpx_codec_enc_cfg_t
struct vpx_codec_enc_cfg vpx_codec_enc_cfg_t
Encoder configuration structure.
vpx_codec_enc_init
#define vpx_codec_enc_init(ctx, iface, cfg, flags)
Convenience macro for vpx_codec_enc_init_ver().
Definition vpx_encoder.h:908
VPX_EFLAG_FORCE_KF
#define VPX_EFLAG_FORCE_KF
Definition vpx_encoder.h:269
VPX_DL_GOOD_QUALITY
#define VPX_DL_GOOD_QUALITY
deadline parameter analogous to VPx GOOD QUALITY mode.
Definition vpx_encoder.h:1019
vpx_codec_get_cx_data
const vpx_codec_cx_pkt_t * vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter)
Encoded data iterator.
vpx_codec_er_flags_t
uint32_t vpx_codec_er_flags_t
Error Resilient flags.
Definition vpx_encoder.h:138
VPX_FRAME_IS_KEY
#define VPX_FRAME_IS_KEY
Definition vpx_encoder.h:123
vpx_codec_enc_config_default
vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface, vpx_codec_enc_cfg_t *cfg, unsigned int usage)
Get a default configuration.
vpx_codec_cx_pkt_t
struct vpx_codec_cx_pkt vpx_codec_cx_pkt_t
Encoder output packet.
vpx_codec_encode
vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx, const vpx_image_t *img, vpx_codec_pts_t pts, unsigned long duration, vpx_enc_frame_flags_t flags, vpx_enc_deadline_t deadline)
Encode a frame.
VPX_CODEC_CX_FRAME_PKT
@ VPX_CODEC_CX_FRAME_PKT
Definition vpx_encoder.h:155
vpx_codec_cx_pkt::data
union vpx_codec_cx_pkt::@105367030154200007005241002351245163342006201240 data
vpx_codec_cx_pkt::frame
struct vpx_codec_cx_pkt::@105367030154200007005241002351245163342006201240::@337301343345304110063267327113124066016321050157 frame
vpx_codec_cx_pkt::flags
vpx_codec_frame_flags_t flags
Definition vpx_encoder.h:177
vpx_codec_cx_pkt::kind
enum vpx_codec_cx_pkt_kind kind
Definition vpx_encoder.h:168
vpx_codec_cx_pkt::sz
size_t sz
Definition vpx_encoder.h:172
vpx_codec_cx_pkt::buf
void * buf
Definition vpx_encoder.h:171
vpx_codec_cx_pkt::pts
vpx_codec_pts_t pts
time stamp to show frame (in timebase units)
Definition vpx_encoder.h:174
vpx_codec_enc_cfg::g_h
unsigned int g_h
Height of the frame.
Definition vpx_encoder.h:324
vpx_codec_enc_cfg::g_error_resilient
vpx_codec_er_flags_t g_error_resilient
Enable error resilient modes.
Definition vpx_encoder.h:366
vpx_codec_enc_cfg::g_w
unsigned int g_w
Width of the frame.
Definition vpx_encoder.h:315
vpx_codec_enc_cfg::g_timebase
struct vpx_rational g_timebase
Stream timebase units.
Definition vpx_encoder.h:358
vpx_codec_enc_cfg::rc_target_bitrate
unsigned int rc_target_bitrate
Target data rate.
Definition vpx_encoder.h:477
vpx_rational::den
int den
Definition vpx_encoder.h:229
vpx_rational::num
int num
Definition vpx_encoder.h:228
vpx_encoder.h
Describes the encoder algorithm interface to applications.
vpx_img_alloc
vpx_image_t * vpx_img_alloc(vpx_image_t *img, vpx_img_fmt_t fmt, unsigned int d_w, unsigned int d_h, unsigned int align)
Open a descriptor, allocating storage for the underlying image.
VPX_IMG_FMT_I420
@ VPX_IMG_FMT_I420
Definition vpx_image.h:42
vpx_image_t
struct vpx_image vpx_image_t
Image Descriptor.
vpx_img_free
void vpx_img_free(vpx_image_t *img)
Close an image descriptor.