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
59 static const char *exec_name;
60
61 void 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
69 static 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 memcpy((uint8_t *)stats->buf + stats->sz, pkt_buf, pkt_size);
88 stats->sz += pkt_size;
89 }
90 }
91
92 return got_pkts;
93 }
94
95 static int encode_frame(vpx_codec_ctx_t *ctx, const vpx_image_t *img,
96 vpx_codec_pts_t pts, unsigned int duration,
97 vpx_enc_frame_flags_t flags, unsigned int deadline,
98 VpxVideoWriter *writer) {
99 int got_pkts = 0;
100 vpx_codec_iter_t iter = NULL;
101 const vpx_codec_cx_pkt_t *pkt = NULL;
102 const vpx_codec_err_t res =
103 vpx_codec_encode(ctx, img, pts, duration, flags, deadline);
104 if (res != VPX_CODEC_OK) die_codec(ctx, "Failed to encode frame.");
105
106 while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
107 got_pkts = 1;
108 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
109 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
110
111 if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,
112 pkt->data.frame.sz,
113 pkt->data.frame.pts))
114 die_codec(ctx, "Failed to write compressed frame.");
115 printf(keyframe ? "K" : ".");
116 fflush(stdout);
117 }
118 }
119
120 return got_pkts;
121 }
122
123 static vpx_fixed_buf_t pass0(vpx_image_t *raw, FILE *infile,
124 const VpxInterface *encoder,
125 const vpx_codec_enc_cfg_t *cfg, int max_frames) {
126 vpx_codec_ctx_t codec;
127 int frame_count = 0;
128 vpx_fixed_buf_t stats = { NULL, 0 };
129
130 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
131 die_codec(&codec, "Failed to initialize encoder");
132
133 // Calculate frame statistics.
134 while (vpx_img_read(raw, infile)) {
135 ++frame_count;
136 get_frame_stats(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
137 &stats);
138 if (max_frames > 0 && frame_count >= max_frames) break;
139 }
140
141 // Flush encoder.
142 while (get_frame_stats(&codec, NULL, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
143 &stats)) {
144 }
145
146 printf("Pass 0 complete. Processed %d frames.\n", frame_count);
147 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
148
149 return stats;
150 }
151
152 static void pass1(vpx_image_t *raw, FILE *infile, const char *outfile_name,
153 const VpxInterface *encoder, const vpx_codec_enc_cfg_t *cfg,
154 int max_frames) {
155 VpxVideoInfo info = { encoder->fourcc,
156 cfg->g_w,
157 cfg->g_h,
158 { cfg->g_timebase.num, cfg->g_timebase.den } };
159 VpxVideoWriter *writer = NULL;
160 vpx_codec_ctx_t codec;
161 int frame_count = 0;
162
163 writer = vpx_video_writer_open(outfile_name, kContainerIVF, &info);
164 if (!writer) die("Failed to open %s for writing", outfile_name);
165
166 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
167 die_codec(&codec, "Failed to initialize encoder");
168
169 // Encode frames.
170 while (vpx_img_read(raw, infile)) {
171 ++frame_count;
172 encode_frame(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, writer);
173
174 if (max_frames > 0 && frame_count >= max_frames) break;
175 }
176
177 // Flush encoder.
178 while (encode_frame(&codec, NULL, -1, 1, 0, VPX_DL_GOOD_QUALITY, writer)) {
179 }
180
181 printf("\n");
182
183 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
184
185 vpx_video_writer_close(writer);
186
187 printf("Pass 1 complete. Processed %d frames.\n", frame_count);
188 }
189
190 int main(int argc, char **argv) {
191 FILE *infile = NULL;
192 int w, h;
193 vpx_codec_ctx_t codec;
194 vpx_codec_enc_cfg_t cfg;
195 vpx_image_t raw;
196 vpx_codec_err_t res;
197 vpx_fixed_buf_t stats;
198
199 const VpxInterface *encoder = NULL;
200 const int fps = 30; // TODO(dkovalev) add command line argument
201 const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
202 const char *const codec_arg = argv[1];
203 const char *const width_arg = argv[2];
204 const char *const height_arg = argv[3];
205 const char *const infile_arg = argv[4];
206 const char *const outfile_arg = argv[5];
207 int max_frames = 0;
208 exec_name = argv[0];
209
210 if (argc != 7) die("Invalid number of arguments.");
211
212 max_frames = (int)strtol(argv[6], NULL, 0);
213
214 encoder = get_vpx_encoder_by_name(codec_arg);
215 if (!encoder) die("Unsupported codec.");
216
217 w = (int)strtol(width_arg, NULL, 0);
218 h = (int)strtol(height_arg, NULL, 0);
219
220 if (w <= 0 || h <= 0 || (w % 2) != 0 || (h % 2) != 0)
221 die("Invalid frame size: %dx%d", w, h);
222
223 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, w, h, 1))
224 die("Failed to allocate image", w, h);
225
226 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
227
228 // Configuration
229 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
230 if (res) die_codec(&codec, "Failed to get default codec config.");
231
232 cfg.g_w = w;
233 cfg.g_h = h;
234 cfg.g_timebase.num = 1;
235 cfg.g_timebase.den = fps;
236 cfg.rc_target_bitrate = bitrate;
237
238 if (!(infile = fopen(infile_arg, "rb")))
239 die("Failed to open %s for reading", infile_arg);
240
241 // Pass 0
242 cfg.g_pass = VPX_RC_FIRST_PASS;
243 stats = pass0(&raw, infile, encoder, &cfg, max_frames);
244
245 // Pass 1
246 rewind(infile);
247 cfg.g_pass = VPX_RC_LAST_PASS;
248 cfg.rc_twopass_stats_in = stats;
249 pass1(&raw, infile, outfile_arg, encoder, &cfg, max_frames);
250 free(stats.buf);
251
252 vpx_img_free(&raw);
253 fclose(infile);
254
255 return EXIT_SUCCESS;
256 }
vpx_codec_ctx
Codec context structure.
Definition: vpx_codec.h:197
vpx_fixed_buf
Generic fixed size buffer structure.
Definition: vpx_encoder.h:96
vpx_codec_cx_pkt::kind
enum vpx_codec_cx_pkt_kind kind
Definition: vpx_encoder.h:160
vpx_img_free
void vpx_img_free(vpx_image_t *img)
Close an image descriptor.
vpx_codec_enc_cfg::rc_twopass_stats_in
vpx_fixed_buf_t rc_twopass_stats_in
Two-pass stats buffer.
Definition: vpx_encoder.h:447
vpx_codec_enc_cfg
Encoder configuration structure.
Definition: vpx_encoder.h:268
vpx_codec_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
vpx_enc_frame_flags_t
long vpx_enc_frame_flags_t
Encoded Frame Flags.
Definition: vpx_encoder.h:259
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_rational::num
int num
Definition: vpx_encoder.h:219
VPX_CODEC_OK
Operation completed without error.
Definition: vpx_codec.h:92
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_cx_pkt
Encoder output packet.
Definition: vpx_encoder.h:159
vpx_codec_iter_t
const typedef void * vpx_codec_iter_t
Iterator.
Definition: vpx_codec.h:187
vpx_codec_enc_cfg::g_w
unsigned int g_w
Width of the frame.
Definition: vpx_encoder.h:304
VPX_CODEC_CX_FRAME_PKT
Definition: vpx_encoder.h:147
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:741
VPX_CODEC_STATS_PKT
Definition: vpx_encoder.h:148
vpx_codec_pts_t
int64_t vpx_codec_pts_t
Time Stamp Type.
Definition: vpx_encoder.h:106
VPX_RC_LAST_PASS
Definition: vpx_encoder.h:227
vpx_codec_enc_cfg::g_timebase
struct vpx_rational g_timebase
Stream timebase units.
Definition: vpx_encoder.h:343
VPX_IMG_FMT_I420
Definition: vpx_image.h:42
vpx_image
Image Descriptor.
Definition: vpx_image.h:71
vpx_codec_enc_cfg::g_pass
enum vpx_enc_pass g_pass
Multi-pass Encoding Mode.
Definition: vpx_encoder.h:358
vpx_codec_enc_cfg::g_h
unsigned int g_h
Height of the frame.
Definition: vpx_encoder.h:313
vpx_codec_err_t
vpx_codec_err_t
Algorithm return codes.
Definition: vpx_codec.h:90
vpx_codec_cx_pkt::data
union vpx_codec_cx_pkt::@1 data
VPX_RC_FIRST_PASS
Definition: vpx_encoder.h:226
VPX_FRAME_IS_KEY
#define VPX_FRAME_IS_KEY
Definition: vpx_encoder.h:116
vpx_fixed_buf::sz
size_t sz
Definition: vpx_encoder.h:98
vpx_codec_enc_cfg::rc_target_bitrate
unsigned int rc_target_bitrate
Target data rate.
Definition: vpx_encoder.h:460
vpx_fixed_buf::buf
void * buf
Definition: vpx_encoder.h:97
vpx_codec_cx_pkt::twopass_stats
vpx_fixed_buf_t twopass_stats
Definition: vpx_encoder.h:182
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, unsigned long deadline)
Encode a frame.
vpx_rational::den
int den
Definition: vpx_encoder.h:220
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_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.
vpx_encoder.h
Describes the encoder algorithm interface to applications.
VPX_DL_GOOD_QUALITY
#define VPX_DL_GOOD_QUALITY
deadline parameter analogous to VPx GOOD QUALITY mode.
Definition: vpx_encoder.h:832
vpx_codec_cx_pkt::frame
struct vpx_codec_cx_pkt::@1::@2 frame