libagmv - Adaptive Graphics Motion Video

An open-source full-motion video codec optimized for real-time playback on low-end graphical devices.

About

At its core, libagmv is an indexed-colored, block-based full-motion video codec styled and flavored by a bygone era of video codecs such as Interplay MVE, Smacker Video, Caimans Video Codec for the GBA, and the Quake 2 Cinematics video format. libagmv employs classic retro-style video compression techniques of the mid-90s such as classic color quantization, block-based motion compensation, variable block-sizing and block subdivision, intraframe prediction, block copying, minor vector quantization elements, and a simple DPCM based 2:1 audio compression routine, all in an effort to produce high-quality video that can be efficiently decoded in real-time by resource-limited systems, both in the graphical and processing power sense, such as the 16.78MHz clock speed of the Nintendo Game Boy Advance.

Why use AGMV? AGMV serves four purposes:

• It maintains a unique blend of high-quality video and fast decoding for real-time playback on low-end graphical devices.
• It's open-source and has been ported to other platforms such as the Nintendo Game Boy Advance, DS, and Sony PlayStation.
• Its' compression and container formats are flexible and can be extended while maintaining compatibility with older versions.
• It utilizes the RGB color space, the native color space of most graphical devices, to avoid any intermediary color conversion step so that a decoded frame can be immediately blitted to the screen.

GBA Video Demo

output.mp4

PSX Video Demo

out.mp4

Video Player Demo

agmvp_out.mp4

Example Programs

Simple Video Encoding

#include <stdio.h>
#include <agmv.h>
#include <agidl.h>

int main(){
	AGMV* agmv = CreateAGMV(212,320,240,24); /* (Number of Frames, Width, Height, Frames per Second) */
	AGMV_WavToAudioTrack("example.wav",agmv);
	AGMV_EncodeAGMV(agmv,"example.agmv","example_directory","agmv_base_name",AGMV_IMG_BMP,1,212,320,240,24,AGMV_OPT_III,AGMV_HIGH_QUALITY,AGMV_LZSS_COMPRESSION);
	
	return 0;
}

Simple GBA Video Encoding

#include <stdio.h>
#include <agmv.h>

int main(){
	u32 total_num_frames = 210;
 	
 	/* GENERATES A C HEADER FILE CONTAINING AGMV VIDEO*/
	AGMV* agmv = CreateAGMV(total_num_frames-1,320,240,24);
	AGMV_RawSignedPCMToAudioTrack("example.raw",agmv,1,16000);
	AGMV_EncodeAGMV(agmv,"example.agmv","example_directory","agmv_base_name",AGMV_IMG_BMP,1,total_num_frames,320,240,24,AGMV_OPT_GBA_I,AGMV_MID_QUALITY,AGMV_LZSS_COMPRESSION);
	
	return 0;
}

Simple Video Decoding

#include <stdio.h>
#include <agmv.h>
#include <agidl.h>

int main(){

	AGMV_DecodeAGMV("example.agmv",AGMV_IMG_BMP,AGMV_AUDIO_WAV);
	
	return 0;
}

Simple Audio Decoding

#include <stdio.h>
#include <agmv.h>
#include <agidl.h>

int main(){

	AGMV_DecodeAudio("example.agmv",AGMV_AUDIO_WAV);
	
	return 0;
}

Simple AVI Video Conversion

#include <stdio.h>
#include <agmv.h>

int main(){

	AGMV_ConvertAVItoAGMV("example.avi",AGMV_OPT_I,AGMV_HIGH_QUALITY,AGMV_NONE_COMPRESSION);
	
	return 0;
}

Commands in FFMPEG to Extract Frames for GBA(v1.1)

1. Convert frame rate of video to 24 frames per second(use 16 if size is really important) ffmpeg -i example.mp4 -filter:v fps=fps=24 new_example.mp4
2. Extract audio from new video and convert to GBA compatible format ffmpeg -i new_example.mp4 -ac 1 -ar 16000 -c:a pcm_u8 example.wav
3. Extract image frames from video ffmpeg -i new_example.mp4 agmv_frame_%d.bmp

Commands in FFMPEG to Extract Frames for GBA(v1.0)

1. Convert frame rate of video to 24 frames per second(use 16 if size is really important) ffmpeg -i example.mp4 -filter:v fps=fps=24 new_example.mp4
2. Extract audio from new video ffmpeg -i new_example.mp4 example.wav
3. Extract image frames from video ffmpeg -i new_example.mp4 agmv_frame_%d.bmp
4. In audacity, drag and drop example.wav
5. Click on Tracks on the top bar and select Mix Stereo Down to Mono if the audio is not already mono.
6. Now, still on Tracks, select resample, and choose 16,000.
7. Next, click on File at the top, Export, then Export Audio.
8. In Save Type, select other compressed files
9. In Header, select Raw(header-less)
10. In encoding, select Signed 8-bit PCM
11. Now, click save