WebM Codec SDK: twopass_encoder

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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, "Usage: %s <codec> <width> <height> <infile> <outfile>\n",
63 exec_name);
64 exit(EXIT_FAILURE);
65 }
66
67 static int get_frame_stats(vpx_codec_ctx_t *ctx,
68 const vpx_image_t *img,
69 vpx_codec_pts_t pts,
70 unsigned int duration,
71 vpx_enc_frame_flags_t flags,
72 unsigned int deadline,
73 vpx_fixed_buf_t *stats) {
74 int got_pkts = 0;
75 vpx_codec_iter_t iter = NULL;
76 const vpx_codec_cx_pkt_t *pkt = NULL;
77 const vpx_codec_err_t res = vpx_codec_encode(ctx, img, pts, duration, flags,
78 deadline);
79 if (res != VPX_CODEC_OK)
80 die_codec(ctx, "Failed to get frame stats.");
81
82 while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
83 got_pkts = 1;
84
85 if (pkt->kind == VPX_CODEC_STATS_PKT) {
86 const uint8_t *const pkt_buf = pkt->data.twopass_stats.buf;
87 const size_t pkt_size = pkt->data.twopass_stats.sz;
88 stats->buf = realloc(stats->buf, stats->sz + pkt_size);
89 memcpy((uint8_t *)stats->buf + stats->sz, pkt_buf, pkt_size);
90 stats->sz += pkt_size;
91 }
92 }
93
94 return got_pkts;
95 }
96
97 static int encode_frame(vpx_codec_ctx_t *ctx,
98 const vpx_image_t *img,
99 vpx_codec_pts_t pts,
100 unsigned int duration,
101 vpx_enc_frame_flags_t flags,
102 unsigned int deadline,
103 VpxVideoWriter *writer) {
104 int got_pkts = 0;
105 vpx_codec_iter_t iter = NULL;
106 const vpx_codec_cx_pkt_t *pkt = NULL;
107 const vpx_codec_err_t res = vpx_codec_encode(ctx, img, pts, duration, flags,
108 deadline);
109 if (res != VPX_CODEC_OK)
110 die_codec(ctx, "Failed to encode frame.");
111
112 while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
113 got_pkts = 1;
114 if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
115 const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
116
117 if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,
118 pkt->data.frame.sz,
119 pkt->data.frame.pts))
120 die_codec(ctx, "Failed to write compressed frame.");
121 printf(keyframe ? "K" : ".");
122 fflush(stdout);
123 }
124 }
125
126 return got_pkts;
127 }
128
129 static vpx_fixed_buf_t pass0(vpx_image_t *raw,
130 FILE *infile,
131 const VpxInterface *encoder,
132 const vpx_codec_enc_cfg_t *cfg) {
133 vpx_codec_ctx_t codec;
134 int frame_count = 0;
135 vpx_fixed_buf_t stats = {NULL, 0};
136
137 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
138 die_codec(&codec, "Failed to initialize encoder");
139
140 // Calculate frame statistics.
141 while (vpx_img_read(raw, infile)) {
142 ++frame_count;
143 get_frame_stats(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
144 &stats);
145 }
146
147 // Flush encoder.
148 while (get_frame_stats(&codec, NULL, frame_count, 1, 0,
149 VPX_DL_GOOD_QUALITY, &stats)) {}
150
151 printf("Pass 0 complete. Processed %d frames.\n", frame_count);
152 if (vpx_codec_destroy(&codec))
153 die_codec(&codec, "Failed to destroy codec.");
154
155 return stats;
156 }
157
158 static void pass1(vpx_image_t *raw,
159 FILE *infile,
160 const char *outfile_name,
161 const VpxInterface *encoder,
162 const vpx_codec_enc_cfg_t *cfg) {
163 VpxVideoInfo info = {
164 encoder->fourcc,
165 cfg->g_w,
166 cfg->g_h,
167 {cfg->g_timebase.num, cfg->g_timebase.den}
168 };
169 VpxVideoWriter *writer = NULL;
170 vpx_codec_ctx_t codec;
171 int frame_count = 0;
172
173 writer = vpx_video_writer_open(outfile_name, kContainerIVF, &info);
174 if (!writer)
175 die("Failed to open %s for writing", outfile_name);
176
177 if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
178 die_codec(&codec, "Failed to initialize encoder");
179
180 // Encode frames.
181 while (vpx_img_read(raw, infile)) {
182 ++frame_count;
183 encode_frame(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, writer);
184 }
185
186 // Flush encoder.
187 while (encode_frame(&codec, NULL, -1, 1, 0, VPX_DL_GOOD_QUALITY, writer)) {}
188
189 printf("\n");
190
191 if (vpx_codec_destroy(&codec))
192 die_codec(&codec, "Failed to destroy codec.");
193
194 vpx_video_writer_close(writer);
195
196 printf("Pass 1 complete. Processed %d frames.\n", frame_count);
197 }
198
199 int main(int argc, char **argv) {
200 FILE *infile = NULL;
201 int w, h;
202 vpx_codec_ctx_t codec;
203 vpx_codec_enc_cfg_t cfg;
204 vpx_image_t raw;
205 vpx_codec_err_t res;
206 vpx_fixed_buf_t stats;
207
208 const VpxInterface *encoder = NULL;
209 const int fps = 30; // TODO(dkovalev) add command line argument
210 const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument
211 const char *const codec_arg = argv[1];
212 const char *const width_arg = argv[2];
213 const char *const height_arg = argv[3];
214 const char *const infile_arg = argv[4];
215 const char *const outfile_arg = argv[5];
216 exec_name = argv[0];
217
218 if (argc != 6)
219 die("Invalid number of arguments.");
220
221 encoder = get_vpx_encoder_by_name(codec_arg);
222 if (!encoder)
223 die("Unsupported codec.");
224
225 w = strtol(width_arg, NULL, 0);
226 h = strtol(height_arg, NULL, 0);
227
228 if (w <= 0 || h <= 0 || (w % 2) != 0 || (h % 2) != 0)
229 die("Invalid frame size: %dx%d", w, h);
230
231 if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, w, h, 1))
232 die("Failed to allocate image", w, h);
233
234 printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
235
236 // Configuration
237 res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
238 if (res)
239 die_codec(&codec, "Failed to get default codec config.");
240
241 cfg.g_w = w;
242 cfg.g_h = h;
243 cfg.g_timebase.num = 1;
244 cfg.g_timebase.den = fps;
245 cfg.rc_target_bitrate = bitrate;
246
247 if (!(infile = fopen(infile_arg, "rb")))
248 die("Failed to open %s for reading", infile_arg);
249
250 // Pass 0
251 cfg.g_pass = VPX_RC_FIRST_PASS;
252 stats = pass0(&raw, infile, encoder, &cfg);
253
254 // Pass 1
255 rewind(infile);
256 cfg.g_pass = VPX_RC_LAST_PASS;
257 cfg.rc_twopass_stats_in = stats;
258 pass1(&raw, infile, outfile_arg, encoder, &cfg);
259 free(stats.buf);
260
261 vpx_img_free(&raw);
262 fclose(infile);
263
264 return EXIT_SUCCESS;
265 }
vpx_codec_cx_pkt::twopass_stats
vpx_fixed_buf_t twopass_stats
Definition: vpx_encoder.h:214
vpx_image
Image Descriptor.
Definition: vpx_image.h:88
vpx_encoder.h
Describes the encoder algorithm interface to applications.
vpx_codec_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
vpx_codec_enc_cfg::g_timebase
struct vpx_rational g_timebase
Stream timebase units.
Definition: vpx_encoder.h:397
vpx_rational::den
int den
Definition: vpx_encoder.h:261
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_CODEC_STATS_PKT
Definition: vpx_encoder.h:177
vpx_codec_enc_cfg
Encoder configuration structure.
Definition: vpx_encoder.h:314
vpx_codec_cx_pkt
Encoder output packet.
Definition: vpx_encoder.h:195
vpx_fixed_buf::buf
void * buf
Definition: vpx_encoder.h:109
vpx_fixed_buf
Generic fixed size buffer structure.
Definition: vpx_encoder.h:108
VPX_RC_FIRST_PASS
Definition: vpx_encoder.h:268
VPX_RC_LAST_PASS
Definition: vpx_encoder.h:269
vpx_codec_cx_pkt::frame
struct vpx_codec_cx_pkt::@1::@2 frame
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
Definition: vpx_image.h:56
vpx_codec_enc_cfg::g_w
unsigned int g_w
Width of the frame.
Definition: vpx_encoder.h:357
vpx_codec_enc_cfg::g_h
unsigned int g_h
Height of the frame.
Definition: vpx_encoder.h:367
vpx_codec_cx_pkt::kind
enum vpx_codec_cx_pkt_kind kind
Definition: vpx_encoder.h:196
vpx_enc_frame_flags_t
long vpx_enc_frame_flags_t
Encoded Frame Flags.
Definition: vpx_encoder.h:304
VPX_CODEC_OK
Operation completed without error.
Definition: vpx_codec.h:91
vpx_img_free
void vpx_img_free(vpx_image_t *img)
Close an image descriptor.
vpx_codec_enc_cfg::rc_target_bitrate
unsigned int rc_target_bitrate
Target data rate.
Definition: vpx_encoder.h:525
vpx_rational::num
int num
Definition: vpx_encoder.h:260
vpx_codec_enc_cfg::g_pass
enum vpx_enc_pass g_pass
Multi-pass Encoding Mode.
Definition: vpx_encoder.h:414
VPX_DL_GOOD_QUALITY
#define VPX_DL_GOOD_QUALITY
Definition: vpx_encoder.h:914
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:813
vpx_codec_err_t
vpx_codec_err_t
Algorithm return codes.
Definition: vpx_codec.h:89
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::data
union vpx_codec_cx_pkt::@1 data
vpx_codec_enc_cfg::rc_twopass_stats_in
vpx_fixed_buf_t rc_twopass_stats_in
Two-pass stats buffer.
Definition: vpx_encoder.h:512
vpx_codec_pts_t
int64_t vpx_codec_pts_t
Time Stamp Type.
Definition: vpx_encoder.h:119
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 reserved)
Get a default configuration.
vpx_codec_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.
vpx_fixed_buf::sz
size_t sz
Definition: vpx_encoder.h:110
VPX_FRAME_IS_KEY
#define VPX_FRAME_IS_KEY
Definition: vpx_encoder.h:130
vpx_codec_iter_t
const void * vpx_codec_iter_t
Iterator.
Definition: vpx_codec.h:188
VPX_CODEC_CX_FRAME_PKT
Definition: vpx_encoder.h:176
vpx_codec_ctx
Codec context structure.
Definition: vpx_codec.h:199