WebM Codec SDK: twopass_encoder

WebM Codec SDK

twopass_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// Two Pass Encoder
12// ================
13//
14// This is an example of a two pass encoder loop. It takes an input file in
15// YV12 format, passes it through the encoder twice, and writes the compressed
16// frames to disk in IVF format. It builds upon the simple_encoder example.
17//
18// Twopass Variables
19// -----------------
20// Twopass mode needs to track the current pass number and the buffer of
21// statistics packets.
22//
23// Updating The Configuration
24// ---------------------------------
25// In two pass mode, the configuration has to be updated on each pass. The
26// statistics buffer is passed on the last pass.
27//
28// Encoding A Frame
29// ----------------
30// Encoding a frame in two pass mode is identical to the simple encoder
31// example. To increase the quality while sacrificing encoding speed,
32// VPX_DL_BEST_QUALITY can be used in place of VPX_DL_GOOD_QUALITY.
33//
34// Processing Statistics Packets
35// -----------------------------
36// Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data
37// for this frame. We write a IVF frame header, followed by the raw data.
38//
39//
40// Pass Progress Reporting
41// -----------------------------
42// It's sometimes helpful to see when each pass completes.
43//
44//
45// Clean-up
46// -----------------------------
47// Destruction of the encoder instance must be done on each pass. The
48// raw image should be destroyed at the end as usual.
49
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53
54#include "vpx/vpx_encoder.h"
55
56#include "../tools_common.h"
57#include "../video_writer.h"
58
59static const char *exec_name;
60
61void usage_exit(void) {
62 fprintf(stderr,
63 "Usage: %s <codec> <width> <height> <infile> <outfile> "
64 "<frame limit>\n",
65 exec_name);
66 exit(EXIT_FAILURE);
67}
68
69static int get_frame_stats(vpx_codec_ctx_t *ctx, const vpx_image_t *img,
70 vpx_codec_pts_t pts, unsigned int duration,
71 vpx_enc_frame_flags_t flags, unsigned int deadline,
72 vpx_fixed_buf_t *stats) {
73 int got_pkts = 0;
74 vpx_codec_iter_t iter = NULL;
75 const vpx_codec_cx_pkt_t *pkt = NULL;
76 const vpx_codec_err_t res =
77 vpx_codec_encode(ctx, img, pts, duration, flags, deadline);
78 if (res != VPX_CODEC_OK) die_codec(ctx, "Failed to get frame stats.");
79
80 while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
81 got_pkts = 1;
82
83 if (pkt->kind == VPX_CODEC_STATS_PKT) {
84 const uint8_t *const pkt_buf = pkt->data.twopass_stats.buf;
85 const size_t pkt_size = pkt->data.twopass_stats.sz;
86 stats->buf = realloc(stats->buf, stats->sz + pkt_size);
87 if (!stats->buf) die("Failed to reallocate stats buffer.");
88 memcpy((uint8_t *)stats->buf + stats->sz, pkt_buf, pkt_size);
89 stats->sz += pkt_size;
90 }
91 }
92
93 return got_pkts;
94}
95
96static int encode_frame(vpx_codec_ctx_t *ctx, const vpx_image_t *img,
97 vpx_codec_pts_t pts, unsigned int duration,
98 vpx_enc_frame_flags_t flags, unsigned int deadline,
99 VpxVideoWriter *writer) {
100 int got_pkts = 0;
101 vpx_codec_iter_t iter = NULL;
102 const vpx_codec_cx_pkt_t *pkt = NULL;
103 const vpx_codec_err_t res =
104 vpx_codec_encode(ctx, img, pts, duration, flags, deadline);
105 if (res != VPX_CODEC_OK) die_codec(ctx, "Failed to encode frame.");
106
107 while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
108 got_pkts = 1;
109 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
110 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
111
112 if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,
113 pkt->data.frame.sz,
114 pkt->data.frame.pts))
115 die_codec(ctx, "Failed to write compressed frame.");
116 printf(keyframe ? "K" : ".");
117 fflush(stdout);
118 }
119 }
120
121 return got_pkts;
122}
123
124static vpx_fixed_buf_t pass0(vpx_image_t *raw, FILE *infile,
125 const VpxInterface *encoder,
126 const vpx_codec_enc_cfg_t *cfg, int max_frames) {
127 vpx_codec_ctx_t codec;
128 int frame_count = 0;
129 vpx_fixed_buf_t stats = { NULL, 0 };
130
131 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
132 die("Failed to initialize encoder");
133
134 // Calculate frame statistics.
135 while (vpx_img_read(raw, infile)) {
136 ++frame_count;
137 get_frame_stats(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
138 &stats);
139 if (max_frames > 0 && frame_count >= max_frames) break;
140 }
141
142 // Flush encoder.
143 while (get_frame_stats(&codec, NULL, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
144 &stats)) {
145 }
146
147 printf("Pass 0 complete. Processed %d frames.\n", frame_count);
148 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
149
150 return stats;
151}
152
153static void pass1(vpx_image_t *raw, FILE *infile, const char *outfile_name,
154 const VpxInterface *encoder, const vpx_codec_enc_cfg_t *cfg,
155 int max_frames) {
156 VpxVideoInfo info = { encoder->fourcc,
157 cfg->g_w,
158 cfg->g_h,
159 { cfg->g_timebase.num, cfg->g_timebase.den } };
160 VpxVideoWriter *writer = NULL;
161 vpx_codec_ctx_t codec;
162 int frame_count = 0;
163
164 writer = vpx_video_writer_open(outfile_name, kContainerIVF, &info);
165 if (!writer) die("Failed to open %s for writing", outfile_name);
166
167 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
168 die("Failed to initialize encoder");
169
170 // Encode frames.
171 while (vpx_img_read(raw, infile)) {
172 ++frame_count;
173 encode_frame(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, writer);
174
175 if (max_frames > 0 && frame_count >= max_frames) break;
176 }
177
178 // Flush encoder.
179 while (encode_frame(&codec, NULL, -1, 1, 0, VPX_DL_GOOD_QUALITY, writer)) {
180 }
181
182 printf("\n");
183
184 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
185
186 vpx_video_writer_close(writer);
187
188 printf("Pass 1 complete. Processed %d frames.\n", frame_count);
189}
190
191int main(int argc, char **argv) {
192 FILE *infile = NULL;
193 int w, h;
194 vpx_codec_ctx_t codec;
195 vpx_codec_enc_cfg_t cfg;
196 vpx_image_t raw;
197 vpx_codec_err_t res;
198 vpx_fixed_buf_t stats;
199
200 const VpxInterface *encoder = NULL;
201 const int fps = 30; // TODO(dkovalev) add command line argument
202 const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
203 const char *const codec_arg = argv[1];
204 const char *const width_arg = argv[2];
205 const char *const height_arg = argv[3];
206 const char *const infile_arg = argv[4];
207 const char *const outfile_arg = argv[5];
208 int max_frames = 0;
209 exec_name = argv[0];
210
211 if (argc != 7) die("Invalid number of arguments.");
212
213 max_frames = (int)strtol(argv[6], NULL, 0);
214
215 encoder = get_vpx_encoder_by_name(codec_arg);
216 if (!encoder) die("Unsupported codec.");
217
218 w = (int)strtol(width_arg, NULL, 0);
219 h = (int)strtol(height_arg, NULL, 0);
220
221 if (w <= 0 || h <= 0 || (w % 2) != 0 || (h % 2) != 0)
222 die("Invalid frame size: %dx%d", w, h);
223
224 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, w, h, 1))
225 die("Failed to allocate image (%dx%d)", w, h);
226
227 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
228
229 // Configuration
230 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
231 if (res) die_codec(&codec, "Failed to get default codec config.");
232
233 cfg.g_w = w;
234 cfg.g_h = h;
235 cfg.g_timebase.num = 1;
236 cfg.g_timebase.den = fps;
237 cfg.rc_target_bitrate = bitrate;
238
239 if (!(infile = fopen(infile_arg, "rb")))
240 die("Failed to open %s for reading", infile_arg);
241
242 // Pass 0
243 cfg.g_pass = VPX_RC_FIRST_PASS;
244 stats = pass0(&raw, infile, encoder, &cfg, max_frames);
245
246 // Pass 1
247 rewind(infile);
248 cfg.g_pass = VPX_RC_LAST_PASS;
249 cfg.rc_twopass_stats_in = stats;
250 pass1(&raw, infile, outfile_arg, encoder, &cfg, max_frames);
251 free(stats.buf);
252
253 vpx_img_free(&raw);
254 fclose(infile);
255
256 return EXIT_SUCCESS;
257}
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:903
vpx_fixed_buf_t
struct vpx_fixed_buf vpx_fixed_buf_t
Generic fixed size buffer structure.
VPX_DL_GOOD_QUALITY
#define VPX_DL_GOOD_QUALITY
deadline parameter analogous to VPx GOOD QUALITY mode.
Definition vpx_encoder.h:1014
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_FRAME_IS_KEY
#define VPX_FRAME_IS_KEY
Definition vpx_encoder.h:123
vpx_codec_pts_t
int64_t vpx_codec_pts_t
Time Stamp Type.
Definition vpx_encoder.h:113
vpx_enc_frame_flags_t
long vpx_enc_frame_flags_t
Encoded Frame Flags.
Definition vpx_encoder.h:268
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_STATS_PKT
@ VPX_CODEC_STATS_PKT
Definition vpx_encoder.h:156
VPX_RC_LAST_PASS
@ VPX_RC_LAST_PASS
Definition vpx_encoder.h:236
VPX_RC_FIRST_PASS
@ VPX_RC_FIRST_PASS
Definition vpx_encoder.h:235
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::twopass_stats
vpx_fixed_buf_t twopass_stats
Definition vpx_encoder.h:190
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::rc_twopass_stats_in
vpx_fixed_buf_t rc_twopass_stats_in
Two-pass stats buffer.
Definition vpx_encoder.h:458
vpx_codec_enc_cfg::g_h
unsigned int g_h
Height of the frame.
Definition vpx_encoder.h:324
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:354
vpx_codec_enc_cfg::g_pass
enum vpx_enc_pass g_pass
Multi-pass Encoding Mode.
Definition vpx_encoder.h:369
vpx_codec_enc_cfg::rc_target_bitrate
unsigned int rc_target_bitrate
Target data rate.
Definition vpx_encoder.h:473
vpx_fixed_buf::sz
size_t sz
Definition vpx_encoder.h:105
vpx_fixed_buf::buf
void * buf
Definition vpx_encoder.h:104
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.