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Diffstat (limited to 'media/libvpx/libvpx/examples/simple_encoder.c')
| -rw-r--r-- | media/libvpx/libvpx/examples/simple_encoder.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/examples/simple_encoder.c b/media/libvpx/libvpx/examples/simple_encoder.c new file mode 100644 index 0000000000..dffdd6d7da --- /dev/null +++ b/media/libvpx/libvpx/examples/simple_encoder.c @@ -0,0 +1,247 @@ +/* + * Copyright (c) 2010 The WebM project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +// Simple Encoder +// ============== +// +// This is an example of a simple encoder loop. It takes an input file in +// YV12 format, passes it through the encoder, and writes the compressed +// frames to disk in IVF format. Other decoder examples build upon this +// one. +// +// The details of the IVF format have been elided from this example for +// simplicity of presentation, as IVF files will not generally be used by +// your application. In general, an IVF file consists of a file header, +// followed by a variable number of frames. Each frame consists of a frame +// header followed by a variable length payload. The length of the payload +// is specified in the first four bytes of the frame header. The payload is +// the raw compressed data. +// +// Standard Includes +// ----------------- +// For encoders, you only have to include `vpx_encoder.h` and then any +// header files for the specific codecs you use. In this case, we're using +// vp8. +// +// Getting The Default Configuration +// --------------------------------- +// Encoders have the notion of "usage profiles." For example, an encoder +// may want to publish default configurations for both a video +// conferencing application and a best quality offline encoder. These +// obviously have very different default settings. Consult the +// documentation for your codec to see if it provides any default +// configurations. All codecs provide a default configuration, number 0, +// which is valid for material in the vacinity of QCIF/QVGA. +// +// Updating The Configuration +// --------------------------------- +// Almost all applications will want to update the default configuration +// with settings specific to their usage. Here we set the width and height +// of the video file to that specified on the command line. We also scale +// the default bitrate based on the ratio between the default resolution +// and the resolution specified on the command line. +// +// Initializing The Codec +// ---------------------- +// The encoder is initialized by the following code. +// +// Encoding A Frame +// ---------------- +// The frame is read as a continuous block (size width * height * 3 / 2) +// from the input file. If a frame was read (the input file has not hit +// EOF) then the frame is passed to the encoder. Otherwise, a NULL +// is passed, indicating the End-Of-Stream condition to the encoder. The +// `frame_cnt` is reused as the presentation time stamp (PTS) and each +// frame is shown for one frame-time in duration. The flags parameter is +// unused in this example. The deadline is set to VPX_DL_REALTIME to +// make the example run as quickly as possible. + +// Forced Keyframes +// ---------------- +// Keyframes can be forced by setting the VPX_EFLAG_FORCE_KF bit of the +// flags passed to `vpx_codec_control()`. In this example, we force a +// keyframe every <keyframe-interval> frames. Note, the output stream can +// contain additional keyframes beyond those that have been forced using the +// VPX_EFLAG_FORCE_KF flag because of automatic keyframe placement by the +// encoder. +// +// Processing The Encoded Data +// --------------------------- +// Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data +// for this frame. We write a IVF frame header, followed by the raw data. +// +// Cleanup +// ------- +// The `vpx_codec_destroy` call frees any memory allocated by the codec. +// +// Error Handling +// -------------- +// This example does not special case any error return codes. If there was +// an error, a descriptive message is printed and the program exits. With +// few exeptions, vpx_codec functions return an enumerated error status, +// with the value `0` indicating success. +// +// Error Resiliency Features +// ------------------------- +// Error resiliency is controlled by the g_error_resilient member of the +// configuration structure. Use the `decode_with_drops` example to decode with +// frames 5-10 dropped. Compare the output for a file encoded with this example +// versus one encoded with the `simple_encoder` example. + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "vpx/vpx_encoder.h" + +#include "../tools_common.h" +#include "../video_writer.h" + +static const char *exec_name; + +void usage_exit(void) { + fprintf(stderr, + "Usage: %s <codec> <width> <height> <infile> <outfile> " + "<keyframe-interval> <error-resilient> <frames to encode>\n" + "See comments in simple_encoder.c for more information.\n", + exec_name); + exit(EXIT_FAILURE); +} + +static int encode_frame(vpx_codec_ctx_t *codec, vpx_image_t *img, + int frame_index, int flags, VpxVideoWriter *writer) { + int got_pkts = 0; + vpx_codec_iter_t iter = NULL; + const vpx_codec_cx_pkt_t *pkt = NULL; + const vpx_codec_err_t res = + vpx_codec_encode(codec, img, frame_index, 1, flags, VPX_DL_GOOD_QUALITY); + if (res != VPX_CODEC_OK) die_codec(codec, "Failed to encode frame"); + + while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) { + got_pkts = 1; + + if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) { + const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0; + if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf, + pkt->data.frame.sz, + pkt->data.frame.pts)) { + die_codec(codec, "Failed to write compressed frame"); + } + printf(keyframe ? "K" : "."); + fflush(stdout); + } + } + + return got_pkts; +} + +// TODO(tomfinegan): Improve command line parsing and add args for bitrate/fps. +int main(int argc, char **argv) { + FILE *infile = NULL; + vpx_codec_ctx_t codec; + vpx_codec_enc_cfg_t cfg; + int frame_count = 0; + vpx_image_t raw; + vpx_codec_err_t res; + VpxVideoInfo info = { 0, 0, 0, { 0, 0 } }; + VpxVideoWriter *writer = NULL; + const VpxInterface *encoder = NULL; + const int fps = 30; + const int bitrate = 200; + int keyframe_interval = 0; + int max_frames = 0; + int frames_encoded = 0; + const char *codec_arg = NULL; + const char *width_arg = NULL; + const char *height_arg = NULL; + const char *infile_arg = NULL; + const char *outfile_arg = NULL; + const char *keyframe_interval_arg = NULL; + + exec_name = argv[0]; + + if (argc != 9) die("Invalid number of arguments"); + + codec_arg = argv[1]; + width_arg = argv[2]; + height_arg = argv[3]; + infile_arg = argv[4]; + outfile_arg = argv[5]; + keyframe_interval_arg = argv[6]; + max_frames = (int)strtol(argv[8], NULL, 0); + + encoder = get_vpx_encoder_by_name(codec_arg); + if (!encoder) die("Unsupported codec."); + + info.codec_fourcc = encoder->fourcc; + info.frame_width = (int)strtol(width_arg, NULL, 0); + info.frame_height = (int)strtol(height_arg, NULL, 0); + info.time_base.numerator = 1; + info.time_base.denominator = fps; + + if (info.frame_width <= 0 || info.frame_height <= 0 || + (info.frame_width % 2) != 0 || (info.frame_height % 2) != 0) { + die("Invalid frame size: %dx%d", info.frame_width, info.frame_height); + } + + if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width, + info.frame_height, 1)) { + die("Failed to allocate image."); + } + + keyframe_interval = (int)strtol(keyframe_interval_arg, NULL, 0); + if (keyframe_interval < 0) die("Invalid keyframe interval value."); + + printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface())); + + res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0); + if (res) die_codec(&codec, "Failed to get default codec config."); + + cfg.g_w = info.frame_width; + cfg.g_h = info.frame_height; + cfg.g_timebase.num = info.time_base.numerator; + cfg.g_timebase.den = info.time_base.denominator; + cfg.rc_target_bitrate = bitrate; + cfg.g_error_resilient = (vpx_codec_er_flags_t)strtoul(argv[7], NULL, 0); + + writer = vpx_video_writer_open(outfile_arg, kContainerIVF, &info); + if (!writer) die("Failed to open %s for writing.", outfile_arg); + + if (!(infile = fopen(infile_arg, "rb"))) + die("Failed to open %s for reading.", infile_arg); + + if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0)) + die("Failed to initialize encoder"); + + // Encode frames. + while (vpx_img_read(&raw, infile)) { + int flags = 0; + if (keyframe_interval > 0 && frame_count % keyframe_interval == 0) + flags |= VPX_EFLAG_FORCE_KF; + encode_frame(&codec, &raw, frame_count++, flags, writer); + frames_encoded++; + if (max_frames > 0 && frames_encoded >= max_frames) break; + } + + // Flush encoder. + while (encode_frame(&codec, NULL, -1, 0, writer)) { + } + + printf("\n"); + fclose(infile); + printf("Processed %d frames.\n", frame_count); + + vpx_img_free(&raw); + if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec."); + + vpx_video_writer_close(writer); + + return EXIT_SUCCESS; +} |